Chainsaw Repair

was given two of these saws by the local scrapper monday when I dropped off some junk, he just took twenty bucks off what I got so really no cost to me as I was dumping the crap for someone else. Anyway I fired one up and it ran fast and shook like hell stopped it turned it over and 4 out of 4 crankcase  bolts gone didnt try the second but it too has 4 0ut of 4 crankcase bolts gone, what is the length and thread of these bolts  and I suppose a complete split and reseal would be necessary , I have no idea how this thing started but the over revving indicated a good air leak these are power heads only but I figure if they are to much stuffing around they can go for parts and what model poulan matches these thanks