[AG]

Originally Posted by 73ta

600hp 494" RA manifolds won't flow enough for that engine IMHO.

I agree, 600 hp with headers and I know I'll be killing hp with the RA manifolds. That's why I am struggling with the decision. I'll either use a TII or an RPM intake and dyno the motor with headers first and then with manifolds and then make my decision.

[73ta]

Originally Posted by AG

I agree, 600 hp with headers and I know I'll be killing hp with the RA manifolds. That's why I am struggling with the decision. I'll either use a TII or an RPM intake and dyno the motor with headers first and then with manifolds and then make my decision.

30-50 hp drop was noticeable in my 462" 570 HP engine. Headers are a pain in the ass, but worth it IMHO. Spent money cnc porting heads & intake to gain HP, not going to leave that much on the table. Stocker or under 500 HP manifolds make sense.

[AG]

Originally Posted by 73ta

30-50 hp drop was noticeable in my 462" 570 HP engine. Headers are a pain in the ass, but worth it IMHO. Spent money cnc porting heads & intake to gain HP, not going to leave that much on the table. Stocker or under 500 HP manifolds make sense.

I can't argue with that.

[Jay S]

Anyone seen a PUMP GAS naturally aspirated engine that was dynoed with EXHAUST manifold's that did better on peak power than this Pontiac engine MRE did in the video? Round port? Even from a different engine platform like a modern LS, BBC, Ford 385 series or a Hemi? Not counting header combos or race gas, just something using exhaust manifold’s on pump gas. I am not coming up with anything on pump gas beyond 600? This was 623HP@5700.

Friendly dyno?