Which heads on 1994 magnum block

Block is a standard bore. Pistons are on back order. Just gonna be a fun weekend driver for now. 355 gears. I was kinda going off the 380 horse crate motor and figured with better and or ported heads, better camshaft should be able to make 400. Was going to call cam maker and go with whatever they suggest for cam.
I think the magnum block has a little shorter deck height also then la. Not sure how much that changes stuff and also was planning on going with a thinner head gasket, mr gasket is .029 I think.

Which pistons are on back order? I have KB107 pistons in the 2000 360 magnum engine thats in my 91 dakota sport..I went with trickflow heads and PRW 1.6 Rockers. Also used 3/8th Smith brother oil through push rods. The crank and rods are stock