318 with blow by

80 psi would be fine for a good worn 318.
Evidence of blowby would be oil in the frying pan (air cleaner) ?
If the pcv valve was clogged up you can bet the rubber tube and carb tube is clogged as well. Lay the rubber tube on the ground and beat it with a hammer. Dump the carbon deposits out (or just replace it). Use a 1/4" drill to clean the metal tube at carb base by hand. Twist the drill in , pull it out, wipe it down, repeat.
My 73 318 has 302 thousand miles on it now. Replaced timing chain once, stem oil seals once, oil pump once. distributor once. Carb rebuilt twice.