hmmm... let me think about this a little bit...

ok, gas burner, for now the best i've had is my 300 I6. torquey engine, even at stock, plenty of aftermarket parts for it, and can be built to do things that most V8's can do, and at 2 less cylinders mind you! other than that (for gassers) i'd pick the 460. sure it's a fish, but u never feel the load behind you, no matter how big it is...

for diesels, i'm gonna go w/ the cummins 5.9 12 valve. wat can i say? i'm a sucker for 6 cylinders! next up after that is the 7.3 stroker!