I pulled down a 440 to rebuild a few months ago and there were some problems. I've finally gotten around to doing a close inspection and measuring things and this is what I've found:

The main problem is with the bearings.

The rods and mains mic out to almost NO wear yet about 1/2" down the main bearings on the cap side has quite a bit of wear. Is this from detonation?

The cylinder bores were also straight (no taper) and NO WEAR yet the top rings were broke in the pistons! The ring lands and pistons look good as well. Again, was this from detonation?

Oh yeah the bearings were from 1986 and the motor looked like it had a quickie rebuild.

It came out of a stock looking 4x4 truck so I can't imagine it being over-revved or run hard but stranger things have happened.