You could also use a DT360, it would be a much better fit. That way, at least you may be able to get around a rule or 2 with the engine size. Most of the time the rule states it needed to be a factory offered engine in a pickup. The 466 is a great engine, but the 360 is a more practical swap. Either way, for a sled pull, you'd want the most rpm the rules will allow. At the end of the pull is where it'll see the intense loads, and where you'd most likely find out the weak link.