Spark Plug Reference

Nitro Dave · 02-01-2008, 02:07 AM

**Note: Heat ranges are determined by NGK standards. Not all plug manufacturers follow the same guidelines.

***Note: List is intended for reference only. Please consult with head mfg. and ignition mfg. for proper gap.

****Note: NGK IX and Denso plugs are Iridium.

LT1
Thread – 14mm
Reach - .708”
Socket – 5/8 hex
Seat - Taper
Stock Heat Range: 5
Gap: .050
Plug: NGK TR55 (stock number 3951); NGK TR55IX (stock number 7164); Autolite 764; Champion RS14YC6 (stock number 13); Denso IT-16 (stock number 5325)

Nitrous (one step colder)
Heat range: 6
Gap: .035 - .038
Plug: NGK TR6 (stock number 4177); NGK TR6IX (stock number 3689); Autolite 103; Denso IT-20 (stock number 5326)

Nitrous (two steps colder)
Heat Range: 7
Gap: Consult
Plug: NGK BR7EF (stock number 3346); NGK TR7IX (stock number 3690); Autolite AR94; Denso IT22 (stock number 5327)

LT1 w/ AFR heads
Thread – 14mm
Reach – 3/4”
Socket – 5/8 hex
Seat – Gasket
Stock – MFG Recommendations
Heat Range: 9
Gap: Consult ignition mfg.
Plug: NGK 5672A-9 (stock number 7405); Autolite AR3910; Champion C59YC (stock number 792); Denso IQ27 (stock number 5315); Denso IQ01-27 (stock number 5708)(diagonal platinum ground); Denso IQ02-27 (stock number 5711)(horizontal platinum ground)

Nitrous (one step colder)
Heat Range: 10
Gap: Consult ignition mfg.
Plug: NGK 5672A-10 (stock number 7942); Autolite AR50; Denso IQ31 (stock number 5323)

Nitrous (two steps colder)
Heat Range: 11
Gap: Consult ignition mfg.
Plug: Denso IQ34 (stock number 5324)

LT1 w/ Trick Flow & Edelbrock Heads
Thread – 14mm
Reach – 3/4”
Socket – 5/8 hex
Seat – Gasket

Stock – MFG Recommendations: approx under 9:1 compression
Heat Range: 4
Gap: Consult ignition mfg.
Plug: NGK FR4 (stock number 5155); NGK BKR5EIX (stock number 6341); Autolite 3926; Champion RC12YC (stock number 71); Denso IK16 (stock number 5303)

MFG Recommendations: approx 10.5:1 compression
Heat Range: 5
Gap: Consult ignition mfg.
Plug: NGK FR5 (stock number 7373); Autolite AR3924 (Racing Plug); Autolite 3924; Champion RC9YC (stock number 2075); Denso K20PR-U (stock number 3145); Denso IK20 (stock number 5304)

MFG Recommendations: approx 11:1 compression
Heat Range: 8
Gap: Consult ignition mfg.
Plug: NGK R5672A-8 (stock number 7173); Autolite AR3911; Champion C63YC (stock number 796); Denso IQ24 (stock number 5314)

MFG Recommendations: approx 12:1 compression
Heat Range: 9
Gap: Consult ignition mfg.
Plug: NGK R5672A-9 (stock number 7405); Autolite AR3910; Champion C61YC (stock number 785); Denso IQ27 (stock number 5315)

MFG Recommendations: approx 13:1 compression
Heat Range: 9 - 10
Gap: Consult ignition mfg.
Plug: NGK R5671A-9 (stock number 5238); Autolite AR3933; Champion C59CX (stock number 296); Denso IK27 (stock number 5312)

MFG Recommendations: approx 14:1 compression
Heat Range: 10
Gap: Consult ignition mfg.
Plug: NGK R5671A-10 (stock number 5820); Autolite AR3932; Champion C57CX (stock number 295); Denso IK-31 (stock number 5321)

**NOTE: Use chart for static compression and adjust heat range for nitrous use accordingly.

LS1 Stock and AFR
Thread – 14mm
Reach - .708”
Socket – 5/8 hex
Seat - Taper
Stock Heat Range: 5
Gap: .060
Plug: NGK TR55 (stock number 3951); NGK TR55IX (stock number 7164); Autolite 764; Denso IT-16 (stock number 5325)

Nitrous (one step colder)
Heat Range: 6
Gap: .035 - .038
Plug: NGK TR6 (stock number 4177); NGK TR6IX (stock number 3689); Autolite 103; Denso IT-20 (stock number 5326)

Nitrous (two steps colder)
Heat Range: 7
Gap: Consult
Plug: NGK BR7EF (stock number 3346); NGK TR7IX (stock number 3690); Autolite AR94; Denso IT22 (stock number 5327)

Nitrous (two and a half steps colder)
Heat Range: 8
Gap: Consult
Plug: NGK R5724-8 (stock number 7317); NGK TR8IX (part number 3691); Denso IT-24 (stock number 5328)

Nitrous (three steps colder)
Heat Range: 9
Gap: Consult
Plug: NGK R5724-9 (stock number 7891); Autolite AR93; Denso IT-27

Nitrous (four steps colder)
Heat Range: 10
Gap: Consult
Plug: NGK R5724-10 (stock number 7993); Autolite AR92

LS1 w/ Edelbrock and Dart Heads
Thread – 14mm
Reach – 3/4”
Socket – 5/8 hex
Seat – Gasket

Stock – MFG Recommendations: approx under 9:1 compression
Heat Range: 4
Gap: Consult ignition mfg.
Plug: NGK FR4 (stock number 5155); NGK BKR5EIX (stock number 6341); Autolite 3926; Champion RC12YC (stock number 71); Denso IK16 (stock number 5303)

MFG Recommendations: approx 10.5:1 compression
Heat Range: 5
Gap: Consult ignition mfg.
Plug: NGK FR5 (stock number 7373); Autolite AR3924 (Racing Plug); Autolite 3924; Champion RC9YC (stock number 2075); Denso K20PR-U (stock number 3145); Denso IK20 (stock number 5304)

MFG Recommendations: approx 11:1 compression
Heat Range: 8
Gap: Consult ignition mfg.
Plug: NGK R5672A-8 (stock number 7173); Autolite AR3911; Champion C63YC (stock number 796); Denso IQ24 (stock number 5314)

MFG Recommendations: approx 12:1 compression
Heat Range: 9
Gap: Consult ignition mfg.
Plug: NGK R5672A-9 (stock number 7405); Autolite AR3910; Champion C61YC (stock number 785); Denso IQ27 (stock number 5315)

MFG Recommendations: approx 13:1 compression
Heat Range: 9 - 10
Gap: Consult ignition mfg.
Plug: NGK R5671A-9 (stock number 5238); Autolite AR3933; Champion C59CX (stock number 296); Denso IK27 (stock number 5312)

MFG Recommendations: approx 14:1 compression
Heat Range: 10
Gap: Consult ignition mfg.
Plug: NGK R5671A-10 (stock number 5820); Autolite AR3932; Champion C57CX (stock number 295); Denso IK-31 (stock number 5321)

**NOTE: Use chart for static compression and adjust heat range for nitrous use accordingly.

4.6 Mustang GT
Thread – 14mm
Reach - .708”
Socket – 5/8 hex
Seat - Taper
Stock Heat Range: 5
Gap: .054
Plug: NGK TR55 (stock number 3951); NGK TR55IX (stock number 7164); Motorcraft AWSF-32C (copper); Autolite 764; Denso IT-16 (stock number 5325)

Nitrous (one step colder)
Heat Range: 6
Gap: .035 - .038
Plug: NGK TR6 (stock number 4177); NGK TR6IX (stock number 3689); Motorcraft AWSF-22C (copper); Autolite 103; Denso IT-20 (stock number 5326)

Nitrous (two steps colder)
Heat Range: 7
Gap: Consult
Plug: NGK BR7EF (stock number 3346); NGK TR7IX (stock number 3690); Motorcraft AWSFA-12C (copper); Autolite AR94; Denso IT-22 (stock number 5327)

Nitrous (two and a half steps colder)
Heat Range: 8
Gap: Consult
Plug: NGK R5724-8 (stock number 7317); NGK TR8IX (part number 3691); Denso IT-24 (stock number 5328)

Nitrous (three steps colder)
Heat Range: 9
Gap: Consult
Plug: NGK R5724-9 (stock number 7891); Autolite AR93; Denso IT-27

Nitrous (four steps colder)
Heat Range: 10
Gap: Consult
Plug: NGK R5724-10 (stock number 7993); Autolite AR92

4.6 Mustang Cobra (96-01)
Thread – 14mm
Reach - .708”
Socket – 5/8 hex
Seat - Taper
Stock Heat Range: 5
Gap: .054
Plug: NGK TR55 (stock number 3951); NGK TR55IX (stock number 7164); Autolite 764; Denso IT-16 (stock number 5325)

Nitrous (one step colder)
Heat Range: 6
Gap: .035 - .038
Plug: NGK TR6 (stock number 4177); NGK TR6IX (stock number 3689); Motorcraft AWSF-22C (copper); Autolite 103; Denso IT-20 (stock number 5326)

Nitrous (two steps colder)
Heat Range: 7
Gap: Consult
Plug: NGK BR7EF (stock number 3346); NGK TR7IX (stock number 3690); Motorcraft AWSFA-12C (copper); Autolite AR94; Denso IT22 (stock number 5327)

Nitrous (two and a half steps colder)
Heat Range: 8
Gap: Consult
Plug: NGK R5724-8 (stock number 7317); NGK TR8IX (part number 3691); Denso IT-24 (stock number 5328)

Nitrous (three steps colder)
Heat Range: 9
Gap: Consult
Plug: NGK R5724-9 (stock number 7891); Autolite AR93; Denso IT-27

Nitrous (four steps colder)
Heat Range: 10
Gap: Consult
Plug: NGK R5724-10 (stock number 7993); Autolite AR92

4.6 Mustang Cobra (03-04)
Thread – 14mm
Reach - .708”
Socket – 5/8 hex
Seat - Taper
Stock Heat Range: 6
Gap: .049 - .052 (have had better results with tighter gap)
Plug: NGK TR6 (stock number 4177); NGK TR6IX (stock number 3689); Motorcraft AWSF-22C (copper); Autolite 103; Denso IT-20 (stock number 5326)

Nitrous (one step colder)
Heat Range: 7
Gap: .035 - .038
Plug: NGK BR7EF (stock number 3346); NGK TR7IX (stock number 3690); Motorcraft AWSFA-12C (copper); Autolite AR94; Denso IT-22 (stock number 5327)

Nitrous (two steps colder)
Heat Range: 8
Gap: Consult
Plug: NGK R5724-8 (stock number 7317); NGK TR8IX (stock number 3691); Denso IT-24 (stock number 5328)

5.0 Mustang 87-95
Thread – 14mm
Reach - .460”
Socket – 5/8 hex
Seat – Taper
Stock Heat Range: 4
Gap: .054
Plug: NGK UR45 (stock number 6945); NGK UR45IX (stock number 3207)

Nitrous (one step colder)
Heat Range: 5
Gap: .035 - .038
Plug: NGK UR5 (stock number 2771); NGK UR5IX (stock number 7177)

Nitrous (two steps colder)
Heat Range: 6
Gap: Consult
Plug: NGK UR6 (stock number 7773); NGK UR6IX (stock number 7348)

5.0 Mustang Cobra 93-95 w/ GT-40 Heads
Thread – 14mm
Reach - .708”
Socket – 5/8 hex
Seat - Taper
Stock Heat Range: 5
Gap: .054
Plug: NGK TR55 (stock number 3951); NGK TR55IX (stock number 7164); Autolite 764 or 104; Denso IT-16 (stock number 5325)

Nitrous (one step colder)
Heat Range: 6
Gap: .035 - .038
Plug: NGK TR6 (stock number 4177); NGK TR6IX (stock number 3689); Motorcraft AWSF-22C (copper); Autolite 103; Denso IT-20 (stock number 5326)

Nitrous (two steps colder)
Heat Range: 7
Gap: Consult
Plug: NGK BR7EF (stock number 3346); NGK TR7IX (stock number 3690); Motorcraft AWSFA-12C (copper); Autolite AR94; Denso IT-22 (stock number 5327)

Nitrous (three steps colder)
Heat Range: 8
Gap: Consult
Plug: NGK R5724-8 (stock number 7317); NGK TR8IX (stock number 3691); Denso IT-24 (stock number 5328)

Ford F-150 Lightning (99-04)
Thread – 14mm
Reach - .708”
Socket – 5/8 hex
Seat - Taper
Stock Heat Range: 6
Gap: .049 - .052
Plug: NGK TR6 (stock number 4177); NGK TR6IX (stock number 3689); Motorcraft AWSF-22C (copper); Autolite 103; Denso IT-20 (stock number 5326)

Nitrous (one step colder)
Heat Range: 7
Gap: .035 - .038
Plug: NGK BR7EF (stock number 3346); NGK TR7IX (stock number 3690); Motorcraft AWSFA-12C (copper); Autolite AR94; Denso IT-22 (stock number 5327)

Nitrous (two steps colder)
Heat Range: 8
Gap: .033 - .036
Plug: NGK R5724-8 (stock number 7317); NGK TR8IX (stock number 3691); Denso IT-24 (stock number 5328)

Nitrous (three steps colder)
Heat Range: 9
Gap: Consult
Plug: NGK R5724-9 (stock number 7891); Autolite AR93; Denso IT-27 (stock number 5329)

matt texass · 03-03-2008, 12:14 AM

05+ 4.6 gt's-

Autolite HTO's - 1 heat range colder

Ray@NitroDaves · 03-03-2008, 12:15 PM

Thx for adding

Ray@NitroDaves · 03-05-2008, 01:50 PM

EFI 5.7 Hemi
NGK-5306 (stock heat range) Heat range 4
NGK-4344 (one step) Heat range 5 (up to 150)
NGK-6509 ( 2 step) Heat Range 6 (150-200)
NGK-6510 (3 Step) Heat Range 7 (250+)

6.1 Hemi
NGK-PLZTR5A-13 Platinum Stock heat range
NGK-6509 1 step Colder
NGK-6510 2 Step colder

Ray@NitroDaves · 03-11-2008, 08:41 AM

Thanks to Fastfatboy for this cross reference link.....

http://www.dragstuff.com/techarticle...reference.html

SOUTHERNHOTROD · 03-15-2008, 07:55 AM

Quote:

Originally Posted by Ray@NitroDaves

EFI 5.7 Hemi
NGK-4306 (one step colder)
NGK-5306 (stock heat range)

6.1 Hemi
NGK-PLZTR5A-13 Platinum Stock heat range
NGK-2315 Iridium 1 step Colder
NGK-5107 Iridium 2 Step colder

Thanks to Southern Hot Rod for new information

I also found these NGK V-Power plugs (1 step colder). . . NGK-3672

Ray@NitroDaves · 11-07-2008, 11:31 AM

up dated the HEMI plugs with new part #'s from NGK

john@nitrousoutlet · 06-08-2010, 12:48 PM

Ole 5.0 Mustang ( Not the new mod 5.0 )

TFS, Edelbrock, and AFR Heads:
[14mm, 3/4" Reach, 5/8" Hex, gasket seat]

AUTOLITE
1 step colder--3924 (4) [*recommended starting point]
2 step colder--3923 (3)
-----AR3933 (3) [*recessed tip, racing plug]
-----AR3932 (2) [*recessed tip, racing plug]
-----AR3931 (1) [*recessed tip, racing plug]

NGK
1 step colder--(FR5) 3686 (5) [*recommended starting point]
2 step colder--(BKR6EY) 3696 (6)
-----(R5671A-8) 4554 (8) [*recessed tip, racing plug]
-----(R5671A-9) 5238 (9) [*recessed tip, racing plug]
-----(R5671A-10) 5820 (10) [*recessed tip, racing plug]

MOTORCRAFT
1 step colder--AWSF22C
2 step colder--AWSF32C

BOTTLE FED R/T · 06-10-2010, 09:02 AM

What the hell am I running I have NGK 4306's?

02-01-2008, 02:07 AM	#1
Nitro Dave Tech Adviser Join Date: Jan 2008 Location: Hewitt, TX Posts: 1,135	Spark Plug Reference Note: Heat ranges are determined by NGK standards. Not all plug manufacturers follow the same guidelines. Note: List is intended for reference only. Please consult with head mfg. and ignition mfg. for proper gap. *Note: NGK IX and Denso plugs are Iridium. LT1 Thread – 14mm Reach - .708” Socket – 5/8 hex Seat - Taper Stock Heat Range: 5 Gap: .050 Plug: NGK TR55 (stock number 3951); NGK TR55IX (stock number 7164); Autolite 764; Champion RS14YC6 (stock number 13); Denso IT-16 (stock number 5325) Nitrous (one step colder) Heat range: 6 Gap: .035 - .038 Plug: NGK TR6 (stock number 4177); NGK TR6IX (stock number 3689); Autolite 103; Denso IT-20 (stock number 5326) Nitrous (two steps colder) Heat Range: 7 Gap: Consult Plug: NGK BR7EF (stock number 3346); NGK TR7IX (stock number 3690); Autolite AR94; Denso IT22 (stock number 5327) LT1 w/ AFR heads Thread – 14mm Reach – 3/4” Socket – 5/8 hex Seat – Gasket Stock – MFG Recommendations Heat Range: 9 Gap: Consult ignition mfg. Plug: NGK 5672A-9 (stock number 7405); Autolite AR3910; Champion C59YC (stock number 792); Denso IQ27 (stock number 5315); Denso IQ01-27 (stock number 5708)(diagonal platinum ground); Denso IQ02-27 (stock number 5711)(horizontal platinum ground) Nitrous (one step colder) Heat Range: 10 Gap: Consult ignition mfg. Plug: NGK 5672A-10 (stock number 7942); Autolite AR50; Denso IQ31 (stock number 5323) Nitrous (two steps colder) Heat Range: 11 Gap: Consult ignition mfg. Plug: Denso IQ34 (stock number 5324) LT1 w/ Trick Flow & Edelbrock Heads Thread – 14mm Reach – 3/4” Socket – 5/8 hex Seat – Gasket Stock – MFG Recommendations: approx under 9:1 compression Heat Range: 4 Gap: Consult ignition mfg. Plug: NGK FR4 (stock number 5155); NGK BKR5EIX (stock number 6341); Autolite 3926; Champion RC12YC (stock number 71); Denso IK16 (stock number 5303) MFG Recommendations: approx 10.5:1 compression Heat Range: 5 Gap: Consult ignition mfg. Plug: NGK FR5 (stock number 7373); Autolite AR3924 (Racing Plug); Autolite 3924; Champion RC9YC (stock number 2075); Denso K20PR-U (stock number 3145); Denso IK20 (stock number 5304) MFG Recommendations: approx 11:1 compression Heat Range: 8 Gap: Consult ignition mfg. Plug: NGK R5672A-8 (stock number 7173); Autolite AR3911; Champion C63YC (stock number 796); Denso IQ24 (stock number 5314) MFG Recommendations: approx 12:1 compression Heat Range: 9 Gap: Consult ignition mfg. Plug: NGK R5672A-9 (stock number 7405); Autolite AR3910; Champion C61YC (stock number 785); Denso IQ27 (stock number 5315) MFG Recommendations: approx 13:1 compression Heat Range: 9 - 10 Gap: Consult ignition mfg. Plug: NGK R5671A-9 (stock number 5238); Autolite AR3933; Champion C59CX (stock number 296); Denso IK27 (stock number 5312) MFG Recommendations: approx 14:1 compression Heat Range: 10 Gap: Consult ignition mfg. Plug: NGK R5671A-10 (stock number 5820); Autolite AR3932; Champion C57CX (stock number 295); Denso IK-31 (stock number 5321) NOTE: Use chart for static compression and adjust heat range for nitrous use accordingly. LS1 Stock and AFR Thread – 14mm Reach - .708” Socket – 5/8 hex Seat - Taper Stock Heat Range: 5 Gap: .060 Plug: NGK TR55 (stock number 3951); NGK TR55IX (stock number 7164); Autolite 764; Denso IT-16 (stock number 5325) Nitrous (one step colder) Heat Range: 6 Gap: .035 - .038 Plug: NGK TR6 (stock number 4177); NGK TR6IX (stock number 3689); Autolite 103; Denso IT-20 (stock number 5326) Nitrous (two steps colder) Heat Range: 7 Gap: Consult Plug: NGK BR7EF (stock number 3346); NGK TR7IX (stock number 3690); Autolite AR94; Denso IT22 (stock number 5327) Nitrous (two and a half steps colder) Heat Range: 8 Gap: Consult Plug: NGK R5724-8 (stock number 7317); NGK TR8IX (part number 3691); Denso IT-24 (stock number 5328) Nitrous (three steps colder) Heat Range: 9 Gap: Consult Plug: NGK R5724-9 (stock number 7891); Autolite AR93; Denso IT-27 Nitrous (four steps colder) Heat Range: 10 Gap: Consult Plug: NGK R5724-10 (stock number 7993); Autolite AR92 LS1 w/ Edelbrock and Dart Heads Thread – 14mm Reach – 3/4” Socket – 5/8 hex Seat – Gasket Stock – MFG Recommendations: approx under 9:1 compression Heat Range: 4 Gap: Consult ignition mfg. Plug: NGK FR4 (stock number 5155); NGK BKR5EIX (stock number 6341); Autolite 3926; Champion RC12YC (stock number 71); Denso IK16 (stock number 5303) MFG Recommendations: approx 10.5:1 compression Heat Range: 5 Gap: Consult ignition mfg. Plug: NGK FR5 (stock number 7373); Autolite AR3924 (Racing Plug); Autolite 3924; Champion RC9YC (stock number 2075); Denso K20PR-U (stock number 3145); Denso IK20 (stock number 5304) MFG Recommendations: approx 11:1 compression Heat Range: 8 Gap: Consult ignition mfg. Plug: NGK R5672A-8 (stock number 7173); Autolite AR3911; Champion C63YC (stock number 796); Denso IQ24 (stock number 5314) MFG Recommendations: approx 12:1 compression Heat Range: 9 Gap: Consult ignition mfg. Plug: NGK R5672A-9 (stock number 7405); Autolite AR3910; Champion C61YC (stock number 785); Denso IQ27 (stock number 5315) MFG Recommendations: approx 13:1 compression Heat Range: 9 - 10 Gap: Consult ignition mfg. Plug: NGK R5671A-9 (stock number 5238); Autolite AR3933; Champion C59CX (stock number 296); Denso IK27 (stock number 5312) MFG Recommendations: approx 14:1 compression Heat Range: 10 Gap: Consult ignition mfg. Plug: NGK R5671A-10 (stock number 5820); Autolite AR3932; Champion C57CX (stock number 295); Denso IK-31 (stock number 5321) **NOTE: Use chart for static compression and adjust heat range for nitrous use accordingly. 4.6 Mustang GT Thread – 14mm Reach - .708” Socket – 5/8 hex Seat - Taper Stock Heat Range: 5 Gap: .054 Plug: NGK TR55 (stock number 3951); NGK TR55IX (stock number 7164); Motorcraft AWSF-32C (copper); Autolite 764; Denso IT-16 (stock number 5325) Nitrous (one step colder) Heat Range: 6 Gap: .035 - .038 Plug: NGK TR6 (stock number 4177); NGK TR6IX (stock number 3689); Motorcraft AWSF-22C (copper); Autolite 103; Denso IT-20 (stock number 5326) Nitrous (two steps colder) Heat Range: 7 Gap: Consult Plug: NGK BR7EF (stock number 3346); NGK TR7IX (stock number 3690); Motorcraft AWSFA-12C (copper); Autolite AR94; Denso IT-22 (stock number 5327) Nitrous (two and a half steps colder) Heat Range: 8 Gap: Consult Plug: NGK R5724-8 (stock number 7317); NGK TR8IX (part number 3691); Denso IT-24 (stock number 5328) Nitrous (three steps colder) Heat Range: 9 Gap: Consult Plug: NGK R5724-9 (stock number 7891); Autolite AR93; Denso IT-27 Nitrous (four steps colder) Heat Range: 10 Gap: Consult Plug: NGK R5724-10 (stock number 7993); Autolite AR92 4.6 Mustang Cobra (96-01) Thread – 14mm Reach - .708” Socket – 5/8 hex Seat - Taper Stock Heat Range: 5 Gap: .054 Plug: NGK TR55 (stock number 3951); NGK TR55IX (stock number 7164); Autolite 764; Denso IT-16 (stock number 5325) Nitrous (one step colder) Heat Range: 6 Gap: .035 - .038 Plug: NGK TR6 (stock number 4177); NGK TR6IX (stock number 3689); Motorcraft AWSF-22C (copper); Autolite 103; Denso IT-20 (stock number 5326) Nitrous (two steps colder) Heat Range: 7 Gap: Consult Plug: NGK BR7EF (stock number 3346); NGK TR7IX (stock number 3690); Motorcraft AWSFA-12C (copper); Autolite AR94; Denso IT22 (stock number 5327) Nitrous (two and a half steps colder) Heat Range: 8 Gap: Consult Plug: NGK R5724-8 (stock number 7317); NGK TR8IX (part number 3691); Denso IT-24 (stock number 5328) Nitrous (three steps colder) Heat Range: 9 Gap: Consult Plug: NGK R5724-9 (stock number 7891); Autolite AR93; Denso IT-27 Nitrous (four steps colder) Heat Range: 10 Gap: Consult Plug: NGK R5724-10 (stock number 7993); Autolite AR92 4.6 Mustang Cobra (03-04) Thread – 14mm Reach - .708” Socket – 5/8 hex Seat - Taper Stock Heat Range: 6 Gap: .049 - .052 (have had better results with tighter gap) Plug: NGK TR6 (stock number 4177); NGK TR6IX (stock number 3689); Motorcraft AWSF-22C (copper); Autolite 103; Denso IT-20 (stock number 5326) Nitrous (one step colder) Heat Range: 7 Gap: .035 - .038 Plug: NGK BR7EF (stock number 3346); NGK TR7IX (stock number 3690); Motorcraft AWSFA-12C (copper); Autolite AR94; Denso IT-22 (stock number 5327) Nitrous (two steps colder) Heat Range: 8 Gap: Consult Plug: NGK R5724-8 (stock number 7317); NGK TR8IX (stock number 3691); Denso IT-24 (stock number 5328) 5.0 Mustang 87-95 Thread – 14mm Reach - .460” Socket – 5/8 hex Seat – Taper Stock Heat Range: 4 Gap: .054 Plug: NGK UR45 (stock number 6945); NGK UR45IX (stock number 3207) Nitrous (one step colder) Heat Range: 5 Gap: .035 - .038 Plug: NGK UR5 (stock number 2771); NGK UR5IX (stock number 7177) Nitrous (two steps colder) Heat Range: 6 Gap: Consult Plug: NGK UR6 (stock number 7773); NGK UR6IX (stock number 7348) 5.0 Mustang Cobra 93-95 w/ GT-40 Heads Thread – 14mm Reach - .708” Socket – 5/8 hex Seat - Taper Stock Heat Range: 5 Gap: .054 Plug: NGK TR55 (stock number 3951); NGK TR55IX (stock number 7164); Autolite 764 or 104; Denso IT-16 (stock number 5325) Nitrous (one step colder) Heat Range: 6 Gap: .035 - .038 Plug: NGK TR6 (stock number 4177); NGK TR6IX (stock number 3689); Motorcraft AWSF-22C (copper); Autolite 103; Denso IT-20 (stock number 5326) Nitrous (two steps colder) Heat Range: 7 Gap: Consult Plug: NGK BR7EF (stock number 3346); NGK TR7IX (stock number 3690); Motorcraft AWSFA-12C (copper); Autolite AR94; Denso IT-22 (stock number 5327) Nitrous (three steps colder) Heat Range: 8 Gap: Consult Plug: NGK R5724-8 (stock number 7317); NGK TR8IX (stock number 3691); Denso IT-24 (stock number 5328) Ford F-150 Lightning (99-04) Thread – 14mm Reach - .708” Socket – 5/8 hex Seat - Taper Stock Heat Range: 6 Gap: .049 - .052 Plug: NGK TR6 (stock number 4177); NGK TR6IX (stock number 3689); Motorcraft AWSF-22C (copper); Autolite 103; Denso IT-20 (stock number 5326) Nitrous (one step colder) Heat Range: 7 Gap: .035 - .038 Plug: NGK BR7EF (stock number 3346); NGK TR7IX (stock number 3690); Motorcraft AWSFA-12C (copper); Autolite AR94; Denso IT-22 (stock number 5327) Nitrous (two steps colder) Heat Range: 8 Gap: .033 - .036 Plug: NGK R5724-8 (stock number 7317); NGK TR8IX (stock number 3691); Denso IT-24 (stock number 5328) Nitrous (three steps colder) Heat Range: 9 Gap: Consult Plug: NGK R5724-9 (stock number 7891); Autolite AR93; Denso IT-27 (stock number 5329) __________________

03-03-2008, 12:14 AM	#2
matt texass Nitrous Tech n00bie Join Date: Mar 2008 Posts: 31	05+ 4.6 gt's- Autolite HTO's - 1 heat range colder __________________

03-05-2008, 01:50 PM	#4
Ray@NitroDaves Tech Adviser Join Date: Feb 2008 Location: Temple, Tx Posts: 186	EFI 5.7 Hemi NGK-5306 (stock heat range) Heat range 4 NGK-4344 (one step) Heat range 5 (up to 150) NGK-6509 ( 2 step) Heat Range 6 (150-200) NGK-6510 (3 Step) Heat Range 7 (250+) 6.1 Hemi NGK-PLZTR5A-13 Platinum Stock heat range NGK-6509 1 step Colder NGK-6510 2 Step colder

Last edited by Ray@NitroDaves; 11-07-2008 at 11:30 AM..

11-07-2008, 11:31 AM	#7
Ray@NitroDaves Tech Adviser Join Date: Feb 2008 Location: Temple, Tx Posts: 186	up dated the HEMI plugs with new part #'s from NGK __________________

06-08-2010, 12:48 PM	#8
john@nitrousoutlet Nitrous Tech n00bie Join Date: May 2010 Posts: 3	Ole 5.0 Mustang ( Not the new mod 5.0 ) TFS, Edelbrock, and AFR Heads: [14mm, 3/4" Reach, 5/8" Hex, gasket seat] AUTOLITE 1 step colder--3924 (4) [recommended starting point] 2 step colder--3923 (3) -----AR3933 (3) [recessed tip, racing plug] -----AR3932 (2) [recessed tip, racing plug] -----AR3931 (1) [recessed tip, racing plug] NGK 1 step colder--(FR5) 3686 (5) [recommended starting point] 2 step colder--(BKR6EY) 3696 (6) -----(R5671A-8) 4554 (8) [recessed tip, racing plug] -----(R5671A-9) 5238 (9) [recessed tip, racing plug] -----(R5671A-10) 5820 (10) [recessed tip, racing plug] MOTORCRAFT 1 step colder--AWSF22C 2 step colder--AWSF32C

Last edited by Chris@NitroDaves; 07-07-2010 at 09:52 AM..

03-03-2008, 12:15 PM	#3
Ray@NitroDaves Tech Adviser Join Date: Feb 2008 Location: Temple, Tx Posts: 186	Thx for adding

03-11-2008, 08:41 AM	#5
Ray@NitroDaves Tech Adviser Join Date: Feb 2008 Location: Temple, Tx Posts: 186	Thanks to Fastfatboy for this cross reference link..... http://www.dragstuff.com/techarticle...reference.html

06-10-2010, 09:02 AM	#9
BOTTLE FED R/T Nitrous Addict Join Date: Feb 2009 Location: St.Louis Posts: 416	What the hell am I running I have NGK 4306's? __________________ 311rwhp & 356rwtq N/A 398rwhp & 487rwtq N2O