[raj]

The more common later Olds cylinder heads are junk. They can be dealt with with a die grinder and someone who knows how to port, but the earlier heads are definitely the ones to get. What I like about Pontiac is that the more common stuff is still good such as 5C or 6X heads. It's also easier to build a respectable compression with Pontiac V8's. I still like the Olds configuration of the intake ports and head design overall a little better than Pontiac, but valve spacing can be an issue with Olds heads. Pontiac will take slightly larger valves.

It would depend on the type of car as to which engine I would choose. For a street driver, it's tough to beat a G bodied Cutlass with a 403. None of the G bodied Pontiacs really compare to me since the 301's are a bit of a different engine alltogether from the earlier V8's. I've always been partial to the 1972 Lemans body style, and there's an issue with the factory exhaust manifolds on Olds A bodied cars that would make a conversion from a 350 to a 455 a PITA. Myself, I prefer the 73-77 Cutlass' over the GP's and Lemans' of that era along with the X bodied cars, but that's just me. For an F bodied car, I'd prefer a 455 myself since there's a little weight there and thus a bit more low end, but the 400's can be made to run just fine with that setup. I've never cared too much for the pre-67 cars.

I'm still a little new to the Pontiac scene, but if it's between 350's I like the Olds built 350 better myself. Between the 400 and the 403, it's a tossup but the 400 is definitely a more durable setup while the 403 would be just fine for the street. I'd take a 455 Pontiac over a 455 Olds, though. Piston selection is a definite plus for Pontiac. Just my opinion.