push rods

all right,i have started to assemble me 400 all is going well but on the top end i am wondering if i need stock length push rods or shorter ones.i'm using a new set of 440 source stelth heads milled .040. the block deck is stock. i will be buying new push rods any way just wondering the length to order. and yes the rockers are adjustable,comp cam rockers!:-D