main bearing identification
 

i need to know if anyone has ever pulled the bearings on their 4.3 and couldn't find a size on them. if im right my rod bearings should be standard but my main bearings im told are over sized.
but this motor has never been torn down till now and i cant find any way to decode the #s on the bearings :icon_shrug:

here is the info i have on them if anybody can help

rod bearings
GM 45
18019003
279 E 41

main bearings
GM 45
18019645
27 * F 41 * = an upside down and backwards 3

no clue why gm would use that bas akwards 3 thing. sorry but im tired of searching

this motor is from my 95 s-10 blazer vin w (stock as the day i bought her)

any help will be greatly appreciated.
thank you