HotRodDad,
Just my .02..... If you don't have a good source for running the block/heads casting #'s, might try
www.mortec.com They have alot of good info. As for the 400, I am building up a 406 for my 69 Camaro right now. I went through 4 blocks before one tanked out "good". Cracks in the lifter valley is a very common problem due to the siamesed bores making too much heat. If you are planning on running the 350 crate engine, I would definately rering the sucker at a minimum! You don't want to have to redo this mill any time soon once you get it in the truck. Good luck with it! Keep us posted.
Dano
