Exhaust Manifolds

[Gordon H.]

A friend of mine bought a pair of exhaust manifolds from a person that claimed they were correct for a 69 350-350 . Left one is correct number 3872765 , checks out in my book . Right one is 336711 . I think it's wrong but don't know what it came from . What does it belong to ? Is it a service replacement or came from another G M product ? Any help would be appreciated .

[Jeff G.]

Re: Exhaust Manifolds

Is there a digit missing that number? Looking through my chevy by the numbers book...

[Gordon H.]

Re: Exhaust Manifolds

No numbers missing . My by the numbers book dosen't have it either , These numbers are cast on the manifold . Looks very similar to 3932461 which is correct .

[Jeff G.]

Re: Exhaust Manifolds

Ok then, next step. What is the casting date? Are there bosses in the casting for A.I.R. ?

[Michael W.]

Re: Exhaust Manifolds

That's a legit and failry common casting number. Not sure what the application is though.

[Tom H.]

Re: Exhaust Manifolds

I think that number was universal manifold for left or right. Truck application.

[Brad M.]

Re: Exhaust Manifolds

Any chance that right is a 386711? I think that number may have been one number used in 1972 for small block with A.I.R. (I do not have my 70-72 JG with me at the moment, but seems that it is either 386711 or 368711).

[Joe L.]

Re: Exhaust Manifolds

A friend of mine bought a pair of exhaust manifolds from a person that claimed they were correct for a 69 350-350 . Left one is correct number 3872765 , checks out in my book . Right one is 336711 . I think it's wrong but don't know what it came from . What does it belong to ? Is it a service replacement or came from another G M product ? Any help would be appreciated .

Gordon-----


GM #336711 is a "ram's horn" type exhaust manifold with AIR fittings used for some truck applications during the 1972-76 period. Mostly, it was used for MD and HD trucks since, by that time, they were the main ones using the "ram's horn" style manifolds. It was never used on or cataloged for a Corvette application. It was discontinued from SERVICE in October, 1976 and replaced by GM #372243. In August, 1976 the latter manifold also replaced the GM #3932461 manifold used on many 1969-80 Corvettes.

While the 336711 was not used on Corvettes, the fact that it was superceded by the same manifold that superceded the Corvette manifold strongly implies that it would work ok on Corvettes originally equipped with the 3932461 manifold.

Actually, I don't understand why the GM #336711 or GM #372243 was not used in PRODUCTION for 1977-80 Corvettes, but GM says it was not. Maybe there are some of those out there that would disprove that, though?

By the way, the GM #372243 remains available in SERVICE from GM to this day for about 325 bucks, GM list. In fact, although it was apparently not originally used on Corvettes, it is the only SERVICE manifold for ANY 1953-82 Corvette which remains available from GM.

[Jeff G.]

Re: Exhaust Manifolds

Joe,
I have to say that answer is impressive.

[Gordon H.]

Re: Exhaust Manifolds

I appreciate all the response and tech information. Guess it won't be good for a corvette , but that is not my decission.Thought all the people here would come up with the correct information and wasn't dissapointed .
thank you all very much

[Kenneth H.]

Re: Exhaust Manifolds

Gordon-----


GM #336711 is a "ram's horn" type exhaust manifold with AIR fittings used for some truck applications during the 1972-76 period. Mostly, it was used for MD and HD trucks since, by that time, they were the main ones using the "ram's horn" style manifolds. It was never used on or cataloged for a Corvette application. It was discontinued from SERVICE in October, 1976 and replaced by GM #372243. In August, 1976 the latter manifold also replaced the GM #3932461 manifold used on many 1969-80 Corvettes.

While the 336711 was not used on Corvettes, the fact that it was superceded by the same manifold that superceded the Corvette manifold strongly implies that it would work ok on Corvettes originally equipped with the 3932461 manifold.

Actually, I don't understand why the GM #336711 or GM #372243 was not used in PRODUCTION for 1977-80 Corvettes, but GM says it was not. Maybe there are some of those out there that would disprove that, though?

By the way, the GM #372243 remains available in SERVICE from GM to this day for about 325 bucks, GM list. In fact, although it was apparently not originally used on Corvettes, it is the only SERVICE manifold for ANY 1953-82 Corvette which remains available from GM.

Joe, you're the best!!!

[Steve L.]

Re: Exhaust Manifolds

Gordon-----


GM #336711 is a "ram's horn" type exhaust manifold with AIR fittings used for some truck applications during the 1972-76 period. Mostly, it was used for MD and HD trucks since, by that time, they were the main ones using the "ram's horn" style manifolds. It was never used on or cataloged for a Corvette application. It was discontinued from SERVICE in October, 1976 and replaced by GM #372243. In August, 1976 the latter manifold also replaced the GM #3932461 manifold used on many 1969-80 Corvettes.

While the 336711 was not used on Corvettes, the fact that it was superceded by the same manifold that superceded the Corvette manifold strongly implies that it would work ok on Corvettes originally equipped with the 3932461 manifold.

Actually, I don't understand why the GM #336711 or GM #372243 was not used in PRODUCTION for 1977-80 Corvettes, but GM says it was not. Maybe there are some of those out there that would disprove that, though?

By the way, the GM #372243 remains available in SERVICE from GM to this day for about 325 bucks, GM list. In fact, although it was apparently not originally used on Corvettes, it is the only SERVICE manifold for ANY 1953-82 Corvette which remains available from GM.

In going thru' the old postings looking for manifold 336711,

I wanted to add that one of my original stud bolt holes cracked back around 1978 or 79. I went to the GM dealer who gave me the 336711 manifold as a replacement.

I still have the 3932461 with a small notch out of the threaded hole. I might try and welding the notch closed.

[Joe L.]

Re: Exhaust Manifolds

In going thru' the old postings looking for manifold 336711,

I wanted to add that one of my original stud bolt holes cracked back around 1978 or 79. I went to the GM dealer who gave me the 336711 manifold as a replacement.

I still have the 3932461 with a small notch out of the threaded hole. I might try and welding the notch closed.

Steve-----


It should not be that hard to find a good used 3932461 that doesn't need to be welded.

[Steve L.]

Re: Exhaust Manifolds

Thanks Joe,
Found a couple on ebay. I might try and weld up my original just to see if I can do it. I wouldn't put it in service.