Getting a smallblock to rev

11.5-12.5 comp, port the heads if u can, look into old MOPAR roundy round cams , probably in the 320* duration depot, u can rev 8 grand or so with a few oiling mods and good well preped stock 340 rods and good bolts. The 273 has a small piston that weighs a lot less if u go with custom forged pistons..so ablot less rotating mass.anything u can rev with the rout cam, but it will only last if the oilsystem is up to par.