A shop manual for your truck would be a good thing to have. Otherwise, any Chilton or Motors manual that covers 1966 will have the specs in it and most mechanical repair info as well.
When doing a comp. test, pull all of the plugs, not just one at a time. If the compression is within 5 psi of each other, you probably don't have a problem. Valve adjustment is dependant on whether its solid or hydraulic lifters. I don't have the specs in front of me right now.
