The Stovebolt Site Forums The Shop Area Engine Shop Exhaust manifold year I.D.

I've had this manifold stashed, thinking it's 55.1 back to ? With the wider inner stud spacing than later model.

I tried searching on GMpartswiki, but it's hard to make out the correct numbers 3 vs 8 etc. Got no hits on the various combinations I tried. If you can post the number that might help. That manifold has obviously been modified, with that welded on outlet.

BC - I squinted through my tri-focals and guestimated that casting number to be 3835388. Screenshot below is from a 1957 Chevy MPC. Application list shows fitting 1949 - ALL (Trucks and Pass cars) (excluding D-D and COE) and 1950-53 All - (Trucks and Pass cars) w/216. Casting number applies to GM part number 3691971.

I bought it several years ago, seems to be a good weld job. Thinking it's '55.1 and earlier .
Cast #8835388

Looks like Dan got it. I knew it wouldn't have been 883xxx, as most casting number start at 3, but I misread the 5 as a 6.
Looks like it fits a 216.

Thanks!
P/N 3961971

Is that welded in outlet for dual exhaust or just a repair/reroute? How about posting a picture of the whole manifold.

BC - You got the first 9 and 6 flip-flopped. Correct GM# is 3691971 (shown in my 1957 Chevy MPC screenshot above).

Welded for dual outlet with functioning heat riser valve.
Will find better pic

More pics

Cylinders 4 and 5 will sure breathe easy!

The correct way, or better way, is to add a baffle at the midway point so half the ports use one pipe, the other half use the add on. But since the add on has a terrible angle, it doesn't flow as well as the factory outlet so the engine still doesn't run any better. Without doing some port work down in the heads, it doesn't matter what manifold you install. Cut that extension off, weld up the hole, and you have a good exhaust manifold again.