the way the engine is set up it really starts pulling around 4 k and does so untill 6500 i'd estimate it around 400hp like i said it has a big cam in it how would the strokeing react to the cam?

would there be any machinework/grinding on the block that would have to be performed? and would i have to change the pistons or just rods?

I'm no mechanic so i would have a shop do it, how much more would you estimate it to be, includeing parts and labor, compared to simply rebuilding the engine?