Tunnel ram or no tunnel ram...
It took me a while to find this pic again, I admire your efforts! What is the cross-section of the runner in the plenum area? What is the runner length? What is the trajectory into the head? Does it match what the engine wants? Etc. Also when it's done how ideal is the height in relation to the scoop you want to use? That's why I offer that if a guys willing to do the work, there are better foundations to start with that may not be any more expensive in base material and/or time. Can you explain differently what you meant by the 'only lost 60HP'? Whereas another manifold was 120? What RPM theoretically should the 'long-block' peak at? THANKS!
I'll try to answer all of this as best I can.
I don't even know if I can properly.
I'll have to go out and measure stuff on the tunnel ram though to get the answers.
With the scoop, I'm going to make my own hood and integrated scoop. As soon as I get the engine in the car, I'll have an idea on that.
Prh asked mentioned to me before I had Dyno tested my engine my style of tunnel ram on a very similar build started to lose power after peak. His tests I believe were from 5800-6800.
He told me the manifold he tested dropped 124 HP from peak rpm to 6800 rpm.
We tested mine with the work I did from my also peak 5800 but it only lost 60 HP by the time it reached 6800.
That's the best I can explain it. But I realize it's 2 different dynos, 2 different engines..I don't know all of the specs of the engine he tested except same ci, pretty close cam, intake manifold and 2 850 carbs. I imagine my 2 inch merge spacers help a little to keep the plenum volume higher.
I think my long block should peak 57-5800.
Small cam 264-268 .660-.674 lift.
Trickflow 240s with gasket match blending and port matched intake to head.