318, 340, or 360?

Just picked up a 66 Cuda with a 273 2bbl, auto trans. Thinking about customizing instead of restore to original. Any advise on a larger engine, manual trans, and upgraded suspension would be much appreciated.View attachment 1715078014

depends on what you want.. for me i i had to stay small block, i'd go 360 screw the 318 or 340. i'f go 73-up large bolt pattern disc brakes and 8 3/4 rear end converted to big bolt and big brakes, 1+" torsion bars and eaton rear springs and good shocks to start.. 4 spped? can go regular 833. can do a 833 OD, a passon 833OD (not his new 5 speed)..