Re: Advanced timing for a 360
Unless you are advanced far enough to be causing detonation, the timing won't affect your bearings...
You need to advance your timing by the book, then listen for detonation.
If you do NOT have detonation, you can advance the timing a few degrees at a time until you get detonation, then back the timing off until the audible detonation stops, then back another 3 to 4 degrees to stop the detonation you can't hear.
If you have detonation at the factory setting, you have another problem.
Find that problem and eliminate it first.
Wear on the 'TOP' of the main bearing can only happen if you used the wrong bearings, installed them improperly, or didn't get the crankshaft trued before install.
The block needing align bored will cause the bearings to wear unevenly, but it won't be just the top half of all your bearings.
"I Have The Body Of A God... Buddha"