318 with blow by

Your compression looks okay to me ! No way should you have this issue under normal circumstances.

As someone else asked before - are you using aftermarket valve covers, ie not stock steel ones ? Aftermarket valve covers do not have an oil baffle below the pcv valve on the rocker cover in most cases. Usually there are bosses on the under side of the cover that can be tapped and a flat plate of metal attached to them.

A cheap and dirty way to check is to pull the pcv from the cover and stick a screwdriver down into it and see if it falls down more than about 1/2 to 3/4 of an inch, also take a flashlite and shine in there. If you see something that looks like a plate then its baffled. If it does not appear to have anything under it, pull the cover to inspect.

Ive seen valve covers from moroso that will not allow you to install a baffle you end up using a special grommet that has a baffle of sorts built in to them. I personally do not like these style covers, and would suggest using cast AL valve covers, they always have a way to attach a baffle from the underside.

You also need to check the hose attachment on the base of the carb as someone suggested for vacuum. If its blocked then clean it out.