5.0 Plug P/N's for stock and various head combos

[ryclef331]

For Your Information....

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

 

[tommybunz]

what about world products winsor sr heads

 

[2plus2]

you think tr6 are to cold for 8-10 lbs of boost.

 

[Slow5.0]

Nice post

 

[tommybunz]

im using autolite 5143 plugs for more compression, but i want ngk's does a nuber cross ref.

 

[tommybunz]

5143 hits the valve is there a full thread plug thats a lil shorter i was looking at 3924s what do you think ryclef

 

[ryclef331]

ARe you running stock heads? You cannot run a full reach plug with a head that requires a short plug. The 3924s are longer than stock.

 

[topless95]

heres a good one, when I bought my car it had autolite 25's in it and they were gapped at .035 and it ran soooooo good. I replaced the autolites with bosch +4's and it runs really good (20-22mpg) but I have noticed a drop in performance. I know that most everyone will say ditch the multi electrode platinum plugs, but my question is why would it run so good at .035 as opposed to the recommended .054 gap?? Thanks as always. Oh by the way I picked up reg copper autolite 25's last night.

 

[tommybunz]

World winsor sr.

 

[94Pro-5.0]

damn, i didnt even know this thread was here. would have saved me a headache. I used autolite 3924's for my TFS heads with no probs :thumb:

 

[DFG_magic]

My coupe I just picked up has Edelbrock heads. It's got the 3924's in it so I guess it was done right. :thumb:

 

[ScottyDsntKnow]

Also should have what to gap them at. Honestly unless you're running something super modified gap doesn't matter all THAT much... People run gaps from 35 to 55 and are fine. I gapped mine at 50.

 

[wtkaos]

What about GT40p heads? Do they use the same plugs as the regular GT40 heads? At what gap?

Thanks.

 

[white95]

How about world products windsor jr heads?

 

[mikey94gt]

hmm, I may be swapping spark plugs in the near future, as I dont remember what is in mine, and they are about 20K old. Does anyone here run stock heat range with a H/C/I car? basically, what plug you runnin. btw, Im running a stock bottom end from an 88GT (wanted the forged pistons) with the TFS Street heat combo pack.

 

[ScottyDsntKnow]

This should be a sticky. I use the Autolite 3924s in mine btw and they work great.

 

[mikey94gt]

How about world products windsor jr heads?

Excellent heads, they have been tested a few times if you look around on the internet. Plenty of info about them.

 

[BradleyJP]

How Exactly Do I Read This Chart?

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]

AUTOLITE Spark Plugs:
"stock--stock 25 (5) [14m, .460 Reach, 5/8" Hex]"

What do each of these numbers mean? Obviously the "5/8in. Hex" is simply the size spark plug socket you'd use to install and remove the plugs. What about the rest?:

• 25 (5) ???
• 14m ???
• .460 Reach ???

NGK Spark Plugs:
"stock--(UR45) 6945 (Heat Range - 4) [14m, .460 Reach, 5/8" Hex]"

• UR45 ???
• 6945 ???

Thanks in advance...

 

[94gt306]

I have the AR 3932 plugs in my car they work great with the edelbrock performer rpm heads

 

[MJORDAN]

I have a 95gt stock headed with a Powedyne and 6lbs of boost. Autozone gave me asf42c plugs. I didnt see those listed earlier in the post. What should I run and at what gap with boost. They say to tighten up the gap when running boost. Thanks.