Food for thought.... The combustion chamber of a OEM Hemi head has a diameter of 4.310. Sounds like a good match to me.

Its not an Oldsmobile, so its not limited to only making torque

With ported heads and a proper cam, you can make that a motor build power to at least 6500-7000rpm. A lot of N/A and Nitrous Promod motors are under-square.