Hi Super Sleeper,
A very easy way to check if the block decks are angle milled is you can get a 18"x24"
wood working square. The stock decks are 90deg from each other. Lay the square
from one deck the other. It will lay flat on each deck surface. A quick check that will
show if you need to measure farther. The 18deg valve angle is set in the head milling.
I think the chevy guy's got there angle milling idea from mopar as there small blocks
are 15deg, or as I like to tease them with. A question as I don't remember, are the
lifter banks in the X block 48deg or stock? I think others here are spot on with the
major deck milling, the square will tell you if any angle is there also.
Serious awsome post.
Thank You for it,
Rick