Here's a pic of mine back when I re-did it years ago. No need to retool a non-chev tach, unless that's what you want - factory tach repops (as shown in your 1st post) are available from LMC (part 36-1929:
http://www.lmctruck.com/icatalog/cbe/full.aspx?Page=53) and the like, if I recall correctly. The best candidate vac gauges seem to be early 60's pontiac and chev console-mounted vac gauges - on ebay or at swap meets.
vac gauge install:
http://67-72chevytrucks.com/vboard/s...d.php?t=527354
parking brake lamp mod (you might opt for this after you've wasted your first set of brake shoes
):
http://67-72chevytrucks.com/vboard/s...d.php?t=419932