Use the cam he has, but replace the lifters. Each lifter bore in each engine is bored at slightly differant angles. In a perfect world lifters would piont at the cams center-line, in other words the lifter bores would be registered off of the cam CL. In the real world and in mass production things flex and wear. Pulling a set of lifters out of one block and trying it in a second block is russian rulet. It dont matter if 10 miles or 10,000....the wear pattern is in the lifters and the cam lobes, now your goin g to try to teach an old dog some new tricks. Does this make sense yet? Throw his used lifters away, buy cheap hyd lifters and use his cam if you want, under no circumstances would I trash $1000 in parts by pumping a wiped out cam and lifters thru my engine.