I just purchased a 1978 427 tall deck block off ebay. I wanted to build a big mountain motor, close to 500 cubic in or a little over, but i read in a book the most stroke the block can take is 4.125 with a little griding on the block any thing over that stroke and you have to do some serious grinding on the block , i guess i just want to know how big i can go (cubic inches) without doing alot of grinding?

thanks