67 skylark with a transplanted 455 in it. Looking at another site I found a list of buick big block exhaust casting manifold numbers. It lists 1967 400/430 1238094 right and 1245433 left since no 455 was an option. Looking up to when the 455 shows up it says... 1970 455 1238094 right and 1233451 left. So if the right hand manifold is the same, then the only reason the left hand manifold is different "must" be to avoid bumping into something specific on the car. Am I thinking correct here? That the set listed for 67 will fit a 455 and clear everything that needs clearing? Not that I know where to find manifolds, but it gets me started anyway. Thanks Jon
There's only a slight difference between the '67 and later left manifolds. It has nothing to with fit or outlet position. The '67 actually has runners that are slightly more separated from each other than the later models for slightly better flow but they command a premium price. The later 455 manifolds will fit fine.
I was told that the drivers side '67 manifold was a one year only design. It did flow a little more than the later manifolds, but they were prone to cracking and that is the reason for the redesign-Robert
The 67 driver's side is indeed different. Here's a pic of mine with a set from a 455. The 67 is on the bottom.
