Thread: Square port manifold to Round port heads

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I have a 427 BB Chevy motor that has round/oval port heads. I have bolted on a tri-power manifold that has square ports. I used the square port gaskets. The motor runs well. Will I have any driveability issues, do I need to re jet the carbs. I was told that you can bolt a square port manifold to round port heads, but not visa versa. Can anyone help me with these questions?

Thanks,
DAB

David, remember in kindergarten when you had that board with the round and square holes in it and you tried to put a square peg into a round hole? It didn't work. But you could put the round peg into the square hole, right? Same thing with your manifold, it's a square peg and you're matching it up with a round (oval really) hole. It's a big block chevy, so it's gonna run pretty well regardless of the mismatch of parts, but you'll never know how well it might have run with matched-up parts. The mismatch at the manifold/head port interface will generate turbulence, but again, it'll run o.k.

as tech said it is not the best for hp , but yes you can go square to oval also just use square gaskets , or oval to square just use the same gaskets, square port.