On my 318 pony build, I used 1983 heads. In the center of the head is a small port with the U shaped port around it. I have a Weiland single plane intake, but it only covers the smaller center port leaving U shaped port open. Engine runs great, but I get puffs of exhaust smoke from the U shaped port. Are there a head without the U shaped port, or a way to block it off. Thanks

 

is the intake intended for LA or magnum engines?

 

The intake is an older Weiland made for 340 318 360. It has the angle bolt for non magnum heads, but I think it was made for the before egr heads.

 

that's my guess- pre/post EGR.