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Author Topic:   Matching Heads
Dirt Full Roller

Total posts: 47
posted December 13, 2001 10:04 PM
I have two heads that recently came off a race motor. The heads appear to be the same, which are the small double hump castings. The casting numbers, however are different. One is 3927186 and the other 399149(2). I believe the 2 is missing but this is the closest match I could find in researching these heads.

Anyway, are these heads considered the same physicaly?


Dirt Freak

Total posts: 467
posted December 14, 2001 12:13 AM
If you have a 492 head , then no they are not the same . The 492 head is a much better casting , and I would suggest finding another one , or buying a new one from GM , and having it matched to your existing one .


Hendren Racing Engines
Rutherfordton , NC

Dirt Full Roller

Total posts: 47
posted December 22, 2001 05:50 PM
Do you think the 399149 is a 492 head with the #2 missing? But if they are different, will this cause a problem in how the engine will run? I'm sure they won't flow the same, but will this really make the engine run bad?


[This message has been edited by 69-er (edited December 22, 2001).]

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