cast iron heads vs aluminum for stroked 340

Yep, we ran the TTI headers and Summit Racing $136 headers on the dyno. The TTI headers averaged one horsepower more than the Summit headers from 3000-6000 rpm and, if I remember correctly, the TTI headers made 10 horsepower more @ 6,300 rpm. And we only had to pay $526 more for the TTI headers.

Totally different story with the 340 we tested them on. We had 476HP with the 1 5/8 Summit headers. Went to 1 5/8- 1 3/4 TTI and picked up 40HP and 300rpm. Guess its all in the combo. But we peaked at 7200rpm