I don't think 600 is a limit.. our dragster has a 2 bolt main 340 block.. a 10.7.1 iron w2 headed motor on bottle and has gone 7.28 @ 188 in the 1/4.. with a 325 horse hit that's probably 850ish HP and it hasn't came apart yet.. not to worried about it either.. no hard block is in the block either..
