When I put a 283/350 in my 46 I ran into the same issue. I used the old 265 "Log" manifolds. They don't breath as well as headers but they get the job done. I'm planning to swap to a 327 soon and will look for a solution that breaths a little better then, but they work fine for now.

Rick

http://rides.webshots.com/photo/1235683823033133681SGYpUY

Last edited by Rick Rickard; 06/17/2011 5:06 PM.