There is a company out of Canada that makes a nice head stud kit for these that I have used in the past. I am also told that ARP has studs that will work, they just don't list them for that application, but if you call them, they can set you up.
They are actually pretty good engines, if you can keep the crankcase halves from leaking oil, and the head gaskets from rotting out due to degraded coolant...
Ron, did you end up putting studs on the mains also? If nothing else, at least put the Time-sert thread inserts in there, as they like to pull the threads out of the block. I was told they used long bolts on the mains and heads, with deep bolt holes and the threads at the bottom to cause minimal distortion when under load, but any electralosys plays havoc with the integrity of the threads.
Which heads did you start with, the vin code 9, or vin code y? There was a slight difference in them between the 2.