one of my friends built a numbers matching 426 where he had to find the block and heads seperately for a 990 64 dodge aluminum race car---he later built a 392 stroker/blower motor for a 40 plymouth street rod---he said he spent way more on the 392 and probably would never build another----if you are building a performance engine you will get more HP/$ out of a 400 stroker with aluminum heads----bob