[kieth]

the higher HP 350s' had the 4 bolt mains, the lower hp ones did not, if you are not going more than 300 hp a 2 bolt main block will be fine. As I read your build I did have a thought , since your winters are so harsh (understatement) why don't you leave the camper on the pick up bed, put the bed on blocks outside and use it as additional storage, You can do all the work on the cab, engine, frame etc and the bed is the last thing to go back on. I would really suggest you look for a 91 burb 2wd or 87 pickup that is in fairly good shape, that way you would have all the brake parts, power steering, power brakes etc.....and a 350 tbi fuel injected engine.......I bought one for $1000.00 even used the tilt wheel and the wiring harness........just a thought. Kieth