Square to Round or Round to Square?

[240ADAM]

I've heard that you can put a square port header on a round port head, but you can't put a round port header on a square port head. I've also heard the oposit also. Anyone know the truth to this? I know you should just buy the correct one, but hey If I can get one for cheap than what the hell.

[datsunaholic]

Never, ever put a roundport header on a squareport head (the round ports are significantly smaller, which will make them not seal plus they form a wall that will cause problems).

 

You can put a squareport MANIFOLD on a roundport head, the gasket may or may not last but I've seen it done quite a bit and it works (even one of my trucks has that setup, though I didn't do it). I'd be skeptical with a header, but it should work.

[Jason]

I had a squareport exhaust manifold on my roundport W58 head, it seemed to work for the fellow, but, I changed it out for a desmogged round port exhaust manifold when I put the engine into my wagon.