408 6pack setup

moper said
that intake is restrictive, but it's not a limiter. It's just lower than some others. What heads are on it? It sounds more like a valvetrain issue if it can't rev. The cam should. The heads should. Something's not right.

As above and
Stupid question , but; Are you looking at the torque curve perhaps?

I really like the idea of a 6-pack stroker, but I bet you will be busy with a 5speed!