Has anyone in the past seen exhaust manifolds like this one? I recently acquired this "one" RH Stage 2 cast iron exhaust manifold. It's "raw as cast" and has not had any machining done to it. I'm sure it's around 50 years old. I have a little history on it, but probably not the entire story, therefore I'd like to see if anyone knows the history on these and IF any more exist. I'd especially like to know if the LH side is still available somewhere out there.......... probably in a warehouse or barn environment, or stashed away like gold on someone's shelf somewhere! Let me know your thoughts on this...................
Measure the port locations... could be interesting.... even if it is a Pontiac. I can see that one of middle three bolts being a problem. Match it to a Stage 2 gasket.
Yes, I was going to do that tomorrow as I just picked it up today. I was told it was made for the Stage 2 Buicks by someone that has worked at the "foundry" in which it came from, for many many years. He could be wrong and I'll post what I find out about the gasket alignment tomorrow.
Ram Air Restorations has the best repop of those pieces and may have a casting that would have the right part number to match up the set. https://www.ramairrestoration.com/rm-4-round-port-ram-air-ho-sd-style-factory-headers.html I’ve got a set of ‘68 Ram Air II heads on my ‘68 Firebird coupe and a ‘71 Trans Am with the 455HO round ports. I know correct parts are nearly impossible to find, even the repop round port Long Branch manifolds on my ‘68 can get $1500-2k if one is patient.
I did a quick search.......... you guys are correct. Pontiac reproduction parts........................
Sorry............. I took the guys word and thought I might have had something pretty cool here............... HAHAHA!! Oh well......
one has to wonder how well those center ports seal, with just one bolt. We have enough issues on the Stage 2's, with three bolts.. JW
I was wondering that myself....... then again they are mighty ridged...... I think that one manifold weighs 200lbs!! LOL
They are out there, but sometimes it takes death for those parts to see the light of the day. I have a bud that I have known for years that has a literally million dollar parts collection. Just his engines are worth more than my house. Ever seen three complete Pontiac SDs just sitting in a garage? Two complete Stage 1s next to those? And more NOS stuff than I have ever seek. His thing was buying insurance wrecks when these Vietnam war era cars were only a couple of years old. And a huge "Better grab these while they are still available" mentality.
I’ve always been curious why Pontiac used so few bolts on manifolds. Using only 1 for 2 center ports would seem like an exhaust leak waiting to happen. But we’ve had a set of those round port Ram Air manifolds on one of our Pontiacs for almost 20 years and there has never been an exhaust leak. The regular non-Ram air D-port manifolds have 2 bolts in the center but they only have one bolt at each end (4 bolts total). No issues.
I have a set of ram-air D-Port exhaust manifolds on my Pontiac and they only use one bolt for the center 2 ports (like seen in previous photo) It must be 10-15 years now and I never had any leaks.
Flat is flat until it isn't....I'm thinking once they get real hot they would leak at some point due to warpage. But occasional use with bolts torqued equally they would be OK but not on a production vehicle.
If any of you know a "Pontiac guy" that may want/need this, be sure to get in touch with me..............I like Pontiacs, but I don't own one and probably won't until I'm done playing with cars. LOL
Mercruiser would seal a sbc manifold with only 4 bolts across the whole thing and often with no gasket
