1969 350/300 Head casting 3947041
03-20-2017, 07:16 AM
#2
My '66 has the head casting number shown in the title. Question I have is will the following exhaust manifolds fit properly? They bolted up fine and looked great but I've got some sort of exhaust leak and have not been able to pinpoint it.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Other side:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Other side:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Make sure to inspect the casting for any cracks first. Inspect the mating surface so true with a strait edge. Also inspect the flange to make sure you got it aligned to the exhaust flare, a few degrees off will let it leak.
If the mating surface is not true then you can take to a machinist and have them true it up (a belt sander with 200 might work for a DIY).
If none then try a fresh new gasket and retorque after the first heat cycle.
Otherwise find a good used OEM manifold that is cast and machined much better.
I try to avoid Dorman products when possible. I'm convinced they just buy the Chinese QC rejects from other suppliers orders.
Last edited by Dynra Rockets; 03-20-2017 at 07:46 AM.
The following 2 users liked this post by Dynra Rockets:
MISTERZ06 (03-20-2017),
Tigershark3 (03-20-2017)
03-20-2017, 09:08 AM
#3
Melting Slicks
Thread Starter
Yes, exhaust manifolds interchange to the heads with no issue. Your issue might be the Dorman products, usually they are awful.
Make sure to inspect the casting for any cracks first. Inspect the mating surface so true with a strait edge. Also inspect the flange to make sure you got it aligned to the exhaust flare, a few degrees off will let it leak.
If the mating surface is not true then you can take to a machinist and have them true it up (a belt sander with 200 might work for a DIY).
If none then try a fresh new gasket and retorque after the first heat cycle.
Otherwise find a good used OEM manifold that is cast and machined much better.
I try to avoid Dorman products when possible. I'm convinced they just buy the Chinese QC rejects from other suppliers orders.
Make sure to inspect the casting for any cracks first. Inspect the mating surface so true with a strait edge. Also inspect the flange to make sure you got it aligned to the exhaust flare, a few degrees off will let it leak.
If the mating surface is not true then you can take to a machinist and have them true it up (a belt sander with 200 might work for a DIY).
If none then try a fresh new gasket and retorque after the first heat cycle.
Otherwise find a good used OEM manifold that is cast and machined much better.
I try to avoid Dorman products when possible. I'm convinced they just buy the Chinese QC rejects from other suppliers orders.
