Inline

So, i have 72' and 76' block ( using 76' block, SMW) and when dummy building it to check few clearances, noticed that drilling on block for nr.1 main bearing, blocks off half of the bearing hole opening to provide oil to bearing. Got confused when looked for my spare 72' block, and same thing + no mentions about this on service manual.

So, was this indended by factory, or do i have 2 miss-drilled blocks 4 years apart?

cutlassefi

olds 307 and 403

They are all like that. Some people drill the bearing out and groove out from the feed hole as well.

Inline

Thanks for confirmation to both of you. I leave it as it is then, im not going to make serious power.