Just as RR said....can't tell forsure.....but heres a few things to look for............
1. Look at your main caps.........if a backyarder did it......it'll have punch marks ...........if a shop or someone into the rebuild.....it'll have #'s stamped on it with ther corresponding locations..........#1 will have 1 stamped, #2 will have 2, etc.....
2. Look at your rod caps.............they'll have punch marks or #'s on them, too..............now if there's a corresponding # on the side of the rod.......yes.......its been taken apart.........
3. Rotate the crank slowly.......if theres some numbers stamped or written on ths crankshaft counterweights with metalmarker............its been to the grinders..............
usually........if you look really good.........and don't see any of the numbers..........and pull one rodcap and a maincap.........and you have STD on the bearing shells and mic them and they're standard................I's say its origional...........
Cause if anyone worth their salt would at least label all this stuff and put new bearings and rings in it even if all they did was freshen it up, without any boring of cylinders, honing of rods, or grinding of the crank.........
If I look really closely...........usually I can tell by the machine marks......but I've been dealing with engines for 30+ years......the fully automated machines that do alot of the manufacturing of engine parts makes different machine marks than those of local shops or rebuilders................
