I'm still a fan of the small journal sbc. 30 some years ago we had a roundy round dirt car with a 283 block, 327 crank and bored .060 to make about 316 c.i. we had a 320 limit so 327s weren't legal. Ours was a well built engine and we got 3-4 seasons from the same bottom end running about 7800 rpms at the end of the straight aways. Nobody with a large journal ever got more than one season on a lower end. Going fast just takes cubic money. How fast do you want to go?