3932461 exhaust manifold casting

[Joseph H.]

I have been looking for the correct manifolds for my 69' 350/350. I have seen different variations of the casting on the 3932461 RH manifold, some with and some without 2 square blocks in the casting. Since these manifolds were used on different chevy engines are the ones with the squares correct for the 69' SB Corvette or not?

Thanks for the help..............

[Joe L.]

Re: 3932461 exhaust manifold casting

I have been looking for the correct manifolds for my 69' 350/350. I have seen different variations of the casting on the 3932461 RH manifold, some with and some without 2 square blocks in the casting. Since these manifolds were used on different chevy engines are the ones with the squares correct for the 69' SB Corvette or not?

Thanks for the help..............

Joseph-----


I'm not sure that I know, for sure, what feature you're referring to. However, attached are photos of a known-original 1969 GM #3932461 manifold. ALL 1969 versions of the GM #3932461 were drilled and tapped for AIR fittings (although not all 3932461 ever made were so drilled and tapped).

You will also note from the pictures that these manifolds were dated on the rear side. So, if you find a 3932461 manifold correctly dated for your car, it could have been installed on your car. However, note that the last character on this date code appears to be an "8". If it is an "8", then this sequence omits the year and represents only "G28" (July 28). This just goes to show how "deceiving" certain characters in casting marks can be.

[Terry M.]

Re: 3932461 exhaust manifold casting

Joe,
Early C3 (1968-1972) small block exhaust manifold casting dates do not contain the year -- at least I have never seen a year in the date code, but then I have not seen every Corvette small block exhaust manifold made.

[Joseph H.]

Re: 3932461 exhaust manifold casting

Thanks, all good info. Joe the pic you posted does not have the square blocks in the casting. See the pic I am attaching. I am not so worried about the date codes as they are on the back side anyway. My car has manifolds from a 1970 that are very nice looking and no rust. I am trying to pick up a few items that are not correct, so in the future if I have the engine rebuilt I can make it closer to correct.

[Brad M.]

Re: 3932461 exhaust manifold casting

"at least I have never seen a year in the date code, but then I have not seen every Corvette small block exhaust manifold made"

I also have never seen ones with year in the date code on the back, but once had a LH 3872765 which had a code on the front "SCC 12-10-67".

[John H.]

Re: 3932461 exhaust manifold casting

Joseph -

That manifold casting number was used for many years. FWIW, both the photo and GM casting drawing in Colvin's "Corvette By The Numbers" book show the two square blocks shown in your photo, but there's no info on when they may have been incorporated in the design.

[Keith L.]

Re: 3932461 exhaust manifold casting

Thanks, all good info. Joe the pic you posted does not have the square blocks in the casting. See the pic I am attaching. I am not so worried about the date codes as they are on the back side anyway. My car has manifolds from a 1970 that are very nice looking and no rust. I am trying to pick up a few items that are not correct, so in the future if I have the engine rebuilt I can make it closer to correct.

So are these with the squares the correct ones for 70? Joseph what are the dates? Does it show a year?

[Joseph H.]

Re: 3932461 exhaust manifold casting

Keith,
The part numbers on my car now are LH 3846559 and RH 3932465. I do not have the date codes as the manifolds are still on the vehicle. There are no squares like this on the RH 3932465 manifold that is on my car. I understand these are from a 1970 SB? The pic I listed are some I found for sale, but I saw somewhere that possibly the square block in the casting was not correct for Corvette SB. Again, not so worried about the dates. The person who did the partial restore on my car did a few things correct and then on a few they cut corners, such as the exhaust manifolds. I am never going to have the car judged, but I would like to get it back close to what it should have been.
Thanks,
Joe