Trick Flow small block heads
So, I pose to you the same question, what combination would you go with? I am wondering if something like Comp's XFI or even (gulp) LS style lobe would work better.
I would have NEVER used a dual plane intake. Funny thing is, TF is making a manifold, essentially for these heads, and it's basically a 45 year old design that has the plenum updated. TF isn't stupid. They developed what they thought would work best with that head.
As for cam timing, it's too combination related. But no FING way is 400 inches going to use cam timing that is that short. Duration. And lift. It's too small for what they were doing.
At that displacement, figuring a 3500 pound car, a 3500 converter and a 3.73 gear (maybe 3.55) you need to be in the high 240's for at .050 timing, net lift needs to be at least .550 and because you are induction limited, and gave up a ton of R/S ratio, an LSA of 106-108 is where it needs to be.
With that timing, you can expect a max power RPM of maybe 6200 and shift at 6500, maybe 6600. Maybe.
And, I wouldn't build it with less that an actual, measured 10.75:1 and 11:1 would be better.
If you want to make power higher than that, either make the heads bigger (and now you get to the point where you are out of room), use a 50 degree seat (I'd do that no matter what) and start welding on the intake manifold because it needs to get bigger too. And it just can't be bigger, it needs to be shaped correctly, and that starts with the valve job.