Originally Posted by DiamondPerformance (Post 4520444)

Fountain did a test years ago -

Originally Posted by MILD THUNDER (Post 4520394)

According to pipemax, a build like that maxing at 6000 rpm, making 750ish hp

For low to mid range power, a 2.06 to 2.131 diameter primary, with 18.8 inch x 3.829 to 4.079 diameter collector.

For mid to upper rpm power, a 2.206 to 2.331 diameter primary, with 18.8 inch x 4.079 to 4.579 diameter collector.

Thats a mile, wait, 10 miles, away from a typical stainless marine standard manifold. In the car world, if you stuffed a 750hp 572ci big block in your car, and ran a 1 7/8" shorty header, with a 3" inch collector, someone would smack you across the cheek. :cartman:

I believe MER Performance recently dynoed a 650ish hp 509 build. Made close to 640 with the 2.25 dyno headers. Bolting the stainless marine manfolds on, it made right about 600hp, and lost a bunch of torque as well. About 30ft lbs I think at peak tq .

Originally Posted by endeavour32 (Post 4520427)

Let me know when you guys plan to dyno. If I can just give them to you, that would be the best!

Originally Posted by getrdunn (Post 4520451)

Just keep your Gil's... Might just keep you from getting t-boned. Remember house sold. GC next. Don't fk with me. Lol. Just kidding. I think those exhaust are awesome not only power but looks. See them in person and they grow on you real quick. They look even better in a twin app. Did you ck measurements yet. Warm this weekend.