AutoX86Z28

i just pulled apart my motor and my friend mixed up the mains. i was about to mark them with a marker and then he mixed them up. soo....any special way to tell apart the mains on 4bolt 350?

ede

well# 1 and 5 you ought to be able to figure out pretty quick, if not you might was well stop now. other than that the answer is no. you can check how flat the bores are with a straight edge, if you have a precession straight edge, spec is .0015 or less. if it were my block i'd consider an alighn bore/hone on the mains and it wouldn't matter if they were mixed up or not.

AsphaltAssalter

It's usually pretty easy to tell, with the crappy machine work done by most OEM's odds are if you put the wrong cap in the wrong place there will be a mismatch where the 2 halfs come together at the parting line, just try different caps in different places till it looks like they match up, if that don't work then getting them align-honed is a good idea.

AutoX86Z28

how much is it usually to get it align honed?

we have a machine shop around here....they do amazing work

Streetiron85

In a some cases the main caps are numbered at the factory, mine were on my 88. Either that or the bottom was rebuilt with std size bearings and there was no record of it.
If they're not marked then there's usually a telltale "footprint" left where the mating surfaces have been clamped together.
If you look carefully at the 3 mains in question, where they've been clamped together, you can see which ones have been mated together by just taking your time and examining them carefully in good light.

FstBrd6point3

Inside micrometer and dial indicator.... check them the same way you check to see if your cylinders are round. Beg, borrow, steal.... dont guess

ljnowell

The best way would be to take the box of mains into a reputable machine shop, and tell them what else needs done.