is the intake a eddy dual plane?
If so they have a inherent low peak HP RPM limit due to the manifold being designed for stock muscle cars back in 1968 shruggy
I built a pump gas low deck stroker motor (505 C.I.) with a low deck Eddy intake and 1970 440 carbs, it made peak HP at 5500 RPM and peak torque at 4500 RPM the first time I dyno tested it.
I ended up swapping the heads and cranks shaft to improve the compression ratio and it made peak HP at 5600 RPM and peak torque at 4600 RPM shruggy
I've been racing and winning with Mopars since 1964, I started on a very low budget and ended up assembling all my motors, that stupid six pack motor would make the car run the quickest and fastest by shifting it at or above 7000 RPM shock
Drive it first and see what yours does by shifting it at 5000, then 5500, then at 6000 and above until you find out what your motor likes on the shift RPM up scope
Dyno sheets are one thing that these stupid motors can't read whistling grin
Good luck thumbs

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)