[64gtoj]

Hi Guys, I have a 1964 GTO 389 with stock exhaust manifold and just purchase Pipes downpipe, Can anyone please tell what type of flange gasket I need or if you have Fe-[Pro part number. I remember they are the donuts style gasket.
Thank you

[Sirrotica]

Pontiac engines don't use gaskets they have a tapered surface on both the manifold and pipe flange to seat together. They work same as a valve seats in the cylinder head for their seal.

If you're worried smear a bit of high temp silicone (RTV) before you assemble the two pieces together to fill any minute imperfections in the sealing surfaces. RTV will not burn out when used to seal exhaust pipes together, been using it for many years to seal exhaust joints, works fantastically.

[64gtoj]

Thanks I kinda had a feeling, because nothing would fit
Thank you so much

[b-man]

Brad is correct, the tapered manifold outlet seals directly to the flare on the down pipe on the ‘64 and later exhaust manifolds with no gasket.

However on the ‘63 and earlier manifolds they didn’t have a tapered outlet, a flat gasket was used to seal the down pipe.

Here's a pair of 1959 389 log manifolds.

[64gtoj]

Thank you guys. I installed the header pipe and no leaks

[pfilean]

Parts book seems to imply that in 64 some models (to include B body) still got the non-flared pipe connection. And 63 may have some both ways also. The flared to cone connection got no gasket so if it seals it shouldn't burn out. The flat gasket models had a flat shoulder formed in the pipe so that a little "nipple" of pipe would extent into the manifold and also be a way to center the gasket on the pipe. The gasket was a donut not the style with the bolt hole ears sticking out. The donut gaskets came in two thickness, either 5/64 or 9/64. I prefer the thicker gasket and I think the Walker number is 31-332. When I go to Summit online for Felpro there are so many numbers that it is hard to cross-reference the Walker number to the Felpro. But as you got yours to seal it probably doesn't matter anyway.

[64gtoj]

Thank you Pfilean, yes mine didn't need the gasket.
Thanks guys for all your help

[Doug]

Originally Posted by pfilean

Parts book seems to imply that in 64 some models (to include B body) still got the non-flared pipe connection. And 63 may have some both ways also. The flared to cone connection got no gasket so if it seals it shouldn't burn out. The flat gasket models had a flat shoulder formed in the pipe so that a little "nipple" of pipe would extent into the manifold and also be a way to center the gasket on the pipe. The gasket was a donut not the style with the bolt hole ears sticking out. The donut gaskets came in two thickness, either 5/64 or 9/64. I prefer the thicker gasket and I think the Walker number is 31-332. When I go to Summit online for Felpro there are so many numbers that it is hard to cross-reference the Walker number to the Felpro. But as you got yours to seal it probably doesn't matter anyway.

FWIW:

I have a NOS right side manifold that has a date code of 5-12-64 and a part number of 532311 which is the same as the above 1959 manifold. (see pictures below)

I don't know why I have it since I have only had 428's and 455's and haven't had any 64,65 engine stuff since 1960's.

What's it worth??

[pfilean]

My 1966 parts book does not list a 532311. Of course if for some reason a casting was changed slightly then the casting number would also change. 532312 is listed as the LH for 59-60 all exc T420A and T425A. But by 1964 the RH seems to have numbers like 977XXXX. And if casting irregularities or rust make that last number be a 54 not a 64 it doesn't make sense as that would be very early for a V8 unless some preproduction number. And numbers in the 532xxx range seem to come in about 58 or 59. And casting dates usually had a letter code used somewhere in them. Always some strange happenings.

As for what it might be worth - ??? Can't be a lot of those around but then the demand can't be high either. If someone had one with that casting number that was cracked and he didn't want to weld it up he might really like what you have. Put it in the for sale section of the forum and see if there are any takers. Like maybe the first true green you see.