Blew it up need sugistions

for 500 hp, you only need to think two choices.. One, milder and bigger, or two, snottier and stock displacement. Something to remember, bigger heads are a must to get hp from a large displacement. 500hp is a 440 with decent compression and a big cam or combination of head work and cam. 500hp from a 505 is better heads and that same big cam, only it idles like a kitten. You have to be prepared to buy bigger carbs and preferably run headers. You may find in both cases 440Source products to be a good fit. They are not perfect, and will usually neeed a little work to be made "good", but the value is excellent. I've personally used 5 of his kits in customers' engines from 451 to 512". All five needed something. But all five run great and were much less than others. Brandon does his best to take care of his customers.