15-18 for vac, should be steady (not bounce)...and no on feelers...GMs valve adjust procedures suck...always off (for 5.7 and 4.3)...just warm engine, pull v covers, run engine... (You will lose some oil and make a bit of a mess if you don't have modified v covers for this) back off valve till "clacks" slowly tighten till clack goes away...do this for all valves (16 times) shut down engine ,let cool. Turn all valves 1/2 to 3/4 full turn (do ALL the same). Replace valve cover, check oil. Unless you have solid lifters...BTW, what's my vacuum at idle (Near 0 at WOT I believe)?
I should sign off for the night, and I'll pick up at my earliest convenience. It's the only vehicle I WANT to drive this winter... not that it is necessary that it runs, but I hate it when the things I've got don't play their roll.