Godzilla, their web page is a piece of work, yes, email them.I have several old GM parts manuals as do some other guys here.
head bolts numbers are;3835811 for the longer bolts,3835812 for the shorter bolts.For the mains,839126(1/2) for the rear main bolts,3835867 for front and rear intermediate main bolts(9/16).Flywheel bolts,839756,same for 235-261,283-350.
