Not to throw a wrench in the works here, but what rules are you pullin under?

Pretty sure you'll be ineligible for everything but the top class (and possibly not even that) after you swap to a 360 or a 466.

99% of the rules I've ever read say the engine had to be factory installed in a 1 ton or smaller truck.

You can use 6.6's, or 7.3's, 6.0's, and 6.4's, or 6.7's and 5.9's. That's pretty much your options most places, unless you pull exibition only.

The 466 truck somebody linked pulled exibition only.