Ford Mustang Forums banner

1 - 20 of 162 Posts

·
Registered
Joined
·
403 Posts
Discussion Starter #1 (Edited)
Hi guys I wanted to compile a "quick reference" chart of the most common nitrous spark plugs for 5.0 and 4.6 Mustangs. Here is what I have gather thus far....

5.0
Stock E7 heads:
AUTOLITE
stock--stock 25 (5) [14m, .460 Reach, 5/8" Hex]
1 step colder--24 (4) [14m, .460 Reach, 5/8" Hex]
2 step colder--23 (3) [14m, .460 Reach, 5/8" Hex]
-----AR133 (3) [*recessed tip, racing plug]
-----AR132 (2) [*recessed tip, racing plug]
-----AR131 (1) [*recessed tip, racing plug]

NGK
stock--(UR45) 6945 (Heat Range - 4) [14m, .460 Reach, 5/8" Hex]
1 step colder--(UR55) 2248 (5) [14m, .460 Reach, 5/8" Hex]
2 step colder--(UR6) 7773 (6) [14m, .460 Reach, 5/8" Hex]
-----(R5673-8) 3249 (8) [*recessed tip, racing plug]
-----(R5673-9) 3442 (9) [*recessed tip, racing plug]
-----(R5673-10) 4050 (10) [*recessed tip, racing plug]


GT40 Heads:
AUTOLITE
stock--765 (Heat Range - 5) [14mm, .708 Reach, 5/8" Hex]
1 step colder--764 (4) or 104 (4) [14mm, .708 Reach, 5/8" Hex]**
2 step colder--103 (3) [14mm, .708 Reach, 5/8" Hex]**
-----AR473 (3) [*recessed tip, racing plug]
-----AR472 (2) [*recessed tip, racing plug]

**The difference between the 764 plug and the 104/103 plug is the thread. The 764 plug is a half thread whereas the 104/103 plug is a full thread. The full thread plugs are duplicates of the half thread plugs in every other aspect, they both protrude the same amount into the combustion chamber.

NGK
stock--(TR4) 3754 (Heat Range - 4) [14mm, .708 Reach, 5/8" Hex]
1 step colder--(TR55) 3951 (5) [14mm, .708 Reach, 5/8" Hex]
2 step colder--(TR6) 4177 (6) [14mm, .708 Reach, 5/8" Hex]
-----(B8EFS) 1049 (8) [*recessed tip, racing plug]
-----(B9EFS) 1085 (9) [*recessed tip, racing plug]

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



4.6
MOTORCRAFT
stock--AWSF-32C (copper)
1 step colder--AWSF-22C (copper)
2 step colder--AWSFA-12C (copper)
AGSF-32C--FRPP heads

NGK
stock--TR-55/ 3951
1 step colder--TR-6 4177
1 step colder--NGK TR6
1 step colder--NGK BR6EF (Non-projected, resistor, v-groove copper)
2 step colder--NGK BR7EF (Non-projected, resistor, v-groove copper)
2 step colder--BP7EFS [PN - 3526] BR7EF [PN - 3346]
2.5 step colder--R5724-8 [PN - 7317]
3 step colder--R5724-9 [PN - 7891]
4 step colder--R5724-10 [PN - 7993]

AUTOLITE
stock--764
1 step colder--103
2 step colder--AR94
3 step colder--AR93
4 step colder--AR92

CHAMPION
YS-59C

DENSO
stock--IT16
1 step colder--IT20
2 step colder--IT22
3 step colder--IT24


Please feel free to correct any errors I have as well as give me part numbers to add. Any help is appreciated!!! I'll be updating this repeatedly
 

·
Registered
Joined
·
403 Posts
Discussion Starter #2
ttt
 

·
Registered
Joined
·
436 Posts
On those 5.0 plugs, its going to depend on the heads. None of those plugs you mention are for stock E7 heads. Autolite 25 are stock, 24s 1 step colder, and 23s 2 steps colder.

On the 4.6s, the NGK TR55 are stock heat range, TR6 1 step colder.

Tony
 

·
Registered
Joined
·
403 Posts
Discussion Starter #5
Thank you LXH89, that's what I was wanting. Corrections and additions to the list. I think it'll be helpfull........

Any more suggestions????
 

·
Premium Member
Joined
·
4,771 Posts
The NGK R5671A-9 is a great nitrous plug. It has a recessed electrode and a shortened ground strap to help avoid detonation. It comes in other heat ranges, with a nine being about 6 or 7 ranges from stock. This plug works on TFS, Edelbrock, and AFR heads. Anything that uses a long reach plug. I have the number for the stock heads as well, but I will have to look at the box later to get the number.
 

·
Registered
Joined
·
436 Posts
For Non-Projected tip plugs on the 4.6 use the following:

NGK BR6EF - 1 Step Colder (Non-projected, resistor, v-groove copper)

NGK BR7EF - 2 Step Colder (same spec as above)

Tony
 

·
Registered
Joined
·
403 Posts
Discussion Starter #8
Awesome and awesome adding those number right now

mustangmichael get back to me whenever you can with those number

LXH89, once again thank you

ttt
 

·
Premium Member
Joined
·
4,771 Posts
GT 40 Heads run a wierd plug, I will check when I get home to see what they are. I have one ported head sitting in the basement, and I can screw a couple of plugs into it to see which one it takes.
 

·
Registered
Joined
·
403 Posts
Discussion Starter #10
ttt
 

·
Registered
Joined
·
403 Posts
Discussion Starter #12
Polygon I'm not totally sure, that's why I wanted everyone's input. Anyone........
 

·
Registered
Joined
·
343 Posts
Hey no big deal mikey, I'm just trying to contribute.

When I got the nitrous kit in, the shop originally sold me Autolite 764's (the plug for the GT-40 heads) because I asked for them by name. When I wanted to go a step colder, they looked it up and discovered that Autolite doesn't make a range colder for the GT-40 heads. They told me to go with the Motorcraft AWSF22C.
 

·
Registered
Joined
·
403 Posts
Discussion Starter #14
No it's GREAT that you are contributing; I'm hoping more will toss in their part numbers!
 

·
Registered
Joined
·
403 Posts
Discussion Starter #15
ttt
 

·
Registered
Joined
·
941 Posts
Edelbrocks can use the autolite (not light) 3924/3923 as well.
 

·
Registered
Joined
·
403 Posts
Discussion Starter #17
Jay thanks for the input, and thanks for the spelling correction!!

HAHA!
 

·
Registered
Joined
·
403 Posts
Discussion Starter #18
Up to the top for some more additions to the list..........
 

·
Registered
Joined
·
1,627 Posts
I use a NGK TR55 and TR6 in my 93 Cobra GT40 irons. I believe the Autolite 103s are 1 range colder than the 764s.

Its been a while since I ran nitrous, but I think I'll be getting another kit soon so I better start remembering. :)
 

·
Registered
Joined
·
403 Posts
Discussion Starter #20
Cool, thanks for the input!
 
1 - 20 of 162 Posts
Top