The TTI head pipes are mandrel bent right off the 340 manifolds no pinch. They flow like giant over sized sewer pipes. TTI routes the head pipes differently depending on auto vs 4 spd. But either way a full 2 1/2 and no exhaust flow choking pinch. Dynomax Ultra Flo mufflers are straight threw zero back pressure and quiet. So one can set up a pretty good flowing exhaust using exhaust manifolds and on the milder builds only sacrificing a tad of power compared to headers.
I really wanted to keep my 340 manifolds but when I went stroker giving up 50-60 hp nope went headers.
