olds307 and 403, agreed. The Gen-V engines are really well-rounded. Lots of power everywhere, fuel-efficient, and refined. If I were going the V-8 route, I might skip all the way to the Gen-V. I'm still a long way from picking out a mill. First step is to get the old 231 at least marginally driveable. Still leaning toward the Caddy LF3 or LF4 turbo six. Actually found one salvage not too far from me for a reasonable price.