CG250 cam for more hp? Low power at Mid rpm

[ProDigit]

I know the pushrod engines don't make lots of hp,but have good torque.

I recently swapped out my Vader 150 engine for a CG250, and while the new engine has more torque, it falls flat in terms of hp.
I was wondering if a different cam could get the engine a bit more air in at higher rpms?
I feel like the 250 should be faster than the 150, but it's not the case.

Just like the 150, I feel like the power gets limited to 5k rpm.
If the engine has sufficient hp to overcome the 5k barrier, it'll continue on to ~7k rpm.
But with the 19/29t and a 140 70 12 tire, the engine can't overcome the 5k rpm barrier in 5th gear (but can in 4th).

I'm wondering if the power dip at the 5k rpm area has to do with the length and diameter of the intake manifold?

Amd if there are manifolds that will angle correctly for the pz30 carburetor to fit in the frame?