Your engine is a 235, not a 250 if it is the original one. There is a lot of speed equipment for that engine. I am in the process of building a hot 235 for my '53 Chevy pickup - milled head for 9:1 compression. 270deg hydraulic cam, aluminum cam gear, clean-up bore & new pistons, Fenton headers & 2" dual exhaust, Holley 600cfm 4-bbl on Clifford manifold, Offy aluminum side cover and valve cover, Chrysler electronic ignition, MSD 5 module, full flow oil filter, Stovebolt tranny adapter and 200R4 OD tranny. Here are a couple of the best sources;
Clifford
Stovebolt