78 280z blue smoke

yes blue smoke means you are burning oil. sitting up fifteen years I'd put my money on valve seals. unlikely a bad ring with those compression numbers but they might not be free and easy in the grooves. You could try the seafoam treatment. Many people on here have had good results with that. When you do a compression test you should have the throttle wide open when getting your numbers.

Gummed/carboned up lazy oil control rings. Short change intervals with HDEO or HDDEO. Marvel Mystery Oil in the crankcase right before you change it. Drive it HARD. Replace the valve stem seals too.

Drive it for a few hundred miles and see what happens. It may have stuck rings and hardened valve seals from sitting and there's a good chance the problem will just clear up with normal usage. Pull the spark plugs and generously squirt some PB blaster directly down each hole and let it sit overnight to help free up the rings. It will smoke when you restart it but burn off in a few seconds.

will attempt pb see what I get what about the valve lash it ticks so should I attempt to tweak them back or wait to warm it up?

Ive been driving the car for weeks now with no major issues besides brakes knock on wood

yes do the valve lash with the motor hot. Cold lash setting is just to get the settings close enough to safely get the motor warmed up.

If the car sat 15+ years ( read Dino straight oil ) and that oil was dirty, when found...
You need some form of solvent to break up the goo holding the rings....
PowerGlide & Ghost tanker have given you a good procedure (s).....
If the motor is smoking ALL the time it's rings ( or a scar on the bore of the cylinder(s) ) ...
If it's on high vacuum or decel mostly it's valve guide seals.

Non turbo, correct?

Mike

Non Turbo, Gonna run today and grab some seafoam and pour some in each cylinder and let it set for 2 days. Then gonna change the oil with one you guys recommend. I have always religiously used Valvoline 10W30 with a Purolator Gold Oil filter

Ok so you don't have the additional " issues " from a turbo belching smoke, due to bad bearing seals... that's good.
If you have ever torn down an engine, there is a bunch of carbon and goo may be stuck in the rings & grooves...

So this is your best shot.... after a good cleaning & some runtime your compression might go up as well.

Might want to clean the PVC valve as well.

Mike