Stock bravo 1 lower

Imco -2\" shorty lower
ok I'm trying to install this imco lower on my bravo 1 upper and I have this oil hole (small white o ring) on my lower and not on my upper and if u notice above the stock lower does not have it so wtf should I do did I buy the wrong lower am I screwed any help would be appreciated

You have an old upper, you need to plug that hole in the lower with a Welch plug

Won't that starve the lower from oil supply

It will still get oil the same as the stock lower did

What is the purpose of that hole ?? Just better circulation

Correct, just tap it out to 5/16 and screw a set screw in it