Here is a link to a GM service manual, Pontiac, Olds, and Chevrolet all used the same engine.
http://oldcarmanualproject.com/manuals/Olds/1966/Chassis/index.htmlStuds are easy to install and are nothing fancy, any local hardware will store will have some that work. 1.5" long should do it.
The two long bolts should stay, the end pins are threaded and can be removed with vise grips.
Follow the manual when tightening the head bolts, except the left front bolt only needs 75 ft lbs where the rest go 95 ft lbs. The block will break if over torqued.
