Factory Bearing Size & Identification

[Luke]

Hi Everyone,

I'm trying to figure out what size main bearings are in my engine. The bearings are all original from a previously unopened '87 109 block. It's pretty clear that main 1 and 3 are .001 bearings (is that undersize or oversize?). As for the rest I'd just be guessing. I've heard that these engines can have different sized bearings in each main from the factory. This block will be going in for align honing/boring anyway but I'd still like to know for my own reference. Any help will be appreciated.

Factory Bearing Notes

Front Main (1):

-Block End, Driver's Side:
A(Circled) GM 66
.001 U.S.
12 86

-Cap End, Driver's Side:
08798
GMMA

-Cap End, Passenger's Side:
318A6


Thrust Main (2):

-Block End, Driver's Side:

19C7
1 (on Notch)

-Block End, Passenger's Side:
57691
GMM 400 (looks like "GMM 40U" due to stamping)

-Cap End, Driver's Side:
57691
GMM 400

-Cap End, Passenger's Side:
20J7


Center Main (3):

-Block End, Driver's Side:
001
14R 731

-Block End, Passenger's Side:
GM 4
18001491

-Cap End, Driver's Side:
14 M 731

-Cap End, Passenger's Side:
GM 4
18001493


Rear Main (4):

-Block End, Driver's Side:
276M6

-Block End, Passenger's Side:
57692
GMMA
1 (on Notch)

-Cap End bearing has wandered off...

 

[pmoore4321]