As you know propane is very kind to bores. the crank/bearings condition would depend alot on how often he changed oil/filter. 100K is ALOT of miles & I would pull several main/rod caps & see what you see. EDIT but with the shortblock out & on a stand it'd be real easy(& cheap) to rering/bearing it & only slightly more effort from there to rebore but you know where you are at with that.