340 motor pumping excess oil on right side

AJ/FormS said

I'm so embarrassed; I missed that rear mounted passenger side breather.

Still, it's odd that this business began after the intake swap.

Click to expand...

Don't be embarrassed I don't think that is the OP problem.
My 340 has a rearward mounted breather on the passenger side which is directly connected to the air cleaner, I have no oiling issues.
Keep looking