to rebuild or just lower end 71 440

I don;t follow you... How do the bores look? What did the bearings look like when you removed them? What did the backsides look like? What do you mean by "rubber"?
sry about that..the engine was built and ran very shortly due to low oil pressure..then taken out and stored... the couple of small thin black rubber pieces I found look like old oil pan gasket.... it all looks new still have cross hatch in the cylinders, had a friend that heard it running said all was great, but the oil pressure...didnt knock or spin any bearings..just light scratches in the bearings. I had the crank turned and have new bearings... ...just wondering if anyone has had any luck just putting in crank and bearings without going through the whole engine...