67 Bonneville Carburetor/Engine size

I have a 67 Bonneville and was wondering how to determine what size engine and what size carburetor. When I'm ordering parts it always ask these questions. There are 4-6 different engine sizes depending on the carburetor and the number of barrels or ports of the carburetor. I should be able to take the air filter off and look at the carburetor and see how many barrels or ports. I think it's two but I'm not sure.

Please advise.

Thanks

2 bbl's have 2 openings of course, a 4bbl has 2 more openings behind the ft 2. All 67's had a 389 engine except the HP 421, I believe.

2 bbl's have 2 openings of course, a 4bbl has 2 more openings behind the ft 2. All 67's had a 389 engine except the HP 421, I believe.

A correction may be required here. 2 separate Wikipedia articles state 1967 was the first year for the 400 V8 and the 428 engine.

I recall the base engine is a 400, 2barrel carb, with a 400/4barrel optional. Also optional, but pretty rare is the 428/4barrel.

I am not sure how to tell the difference between a 400/4bbl and a 428/4bbl.

One concern is if the engine has been swapped at some point in the past 42 years.If the original engine broke at some point in the past, a different one may have been substituted. Virtually all Pontiac V8 engines made from 1955 through 1979 were externally identical, but there are some clues to the origin, including engine serial numbers and the number of engine mount bolts.

Hopefully, MrPbody can help ID this particular engine, if necessary.

You are correct the engines were opened up, my mistake.