Would 66 300 manifolds work? I'd have to double-check that they're not cracked, but pretty sure they're good.
If you don't find one there is a guy just outside of Buffalo NY that i have bought alot of parts from he should have what you need PM me and I can send you his number.
I probably have one. I’m in Omaha NE. Does it have to be a certain casting number or just one that looks like the one in your pic. I have a bunch I have saved from different years etc.
I'll pull them off the motor on the stand and check them later after work this evening and let you know. I'm in KC.
I only have one LH manifold, it looks like 1359688 but unfortunately it has what looks like a crack starting in the usual spot. It’s junk. Sorry.
Mine's got a different number 1375907, but i know that it's not the original one for my car, since I bought this set back in the early 90s from Dave @ NW Buick Performance. Kind of doesn't matter, because it's cracked, too. I had one manifold, might be the pass side of this set, or maybe my original set that had a hole in it that I had a local welding shop braze it up. Never had an issue with it, other than it cracked in a different location. Sorry that I couldn't help. This one is cracked, but not all the way around. You could probably get it brazed and it would probably hold for a while. Problem with all of these factory manifolds is, is if you don't use the locking tabbed keepers that tie one bolt to the other and use the factory torque specs(which is pretty low, if I recall) and the manifolds need to be perfectly flat, they will seal and allow for growth and shrinkage with the heat cycles. If you try to tighten them tighter than recommended, they get constrained and crack. Just a thought...if you're not looking for originality(you probably are, lol), do the Rover's use the same exhaust port spacing? Could Rover manifolds work? Don't know...just wondering out loud.
https://www.facebook.com/marketplace/item/460932209285876/?mibextid=dXMIcH Probably close to you. Part the rest out and get your money back.
