Do you know the condition of the rest of the engine?
Was it rebuilt? When? Cylinders bored? etc.
Good stuff to know before spending big money on aluminum heads.
Sounds to me that you would be better off to spend that money on a fresh rebuild or shortblock before aluminum heads.
Of course I am only troubleshooting from the keyboard...so its hard to tell for me.

 

It's either burning oil or leaking oil,...or a combination of both... before going too far into engine compression/leakdown tests..give the beast a thorough look-over and eliminate the obvious..1st place I'd check is under the dash in the area of the upgraded oil press gauge connection..a leak there could drip into and be absorbed by the carpet/padding and never be noticed..maybe it would run across the floor and puddle in a rear cab corner only to leak on accel..if at all.. (I have seen leaking brand X oil press swx's pump oil thru the elec harness and into the pass compt.)..since the motor mounts were recently replaced, look for the possible oil pressure line chaffing/leakage as a result of moving stuff around in the engine bay.

A loss of 2 qts. a month is ALOT for a leak..there WILL be signs...a leak directly onto a hot exhaust header/pipe may burn away, but there will be signs..take your truck to a trusted mechanic with a vehicle lift, get it up in the air and inspect the undersides real good..front to rear.. with a BRIGHT light..do an oil change at the same time if no signs of a leak are found, it's probably burning it somehow,..check "ALL" vacume source "connections" and look for signs of engine oil (brake booster,distributor,carb base,intake gaskets,PCV system, etc..)..after that ,take time to evaluate what you have found or eliminated..and maybe start considering mechanical failures and tests to pinpoint the problem.

 

...and don't forget those little spacers for the head bolts.

 

The good news is that you really don't have to do oil changes any more; just change the filter every 4,000 miles.

 

I have a company car that is my true daily drive, with the price of gas and all. This is just one of my hobbies I have undertaken to complete the renaissance man package. Besides, all homeowners should have a truck.

 

Smoke on startup and quits is usually valve seals. You've covered PCV operation, recheck to make sure it hasn't clogged. A straight 30w dino oil would be my advise. Synthetic in an older engine sometimes does not work well. Even brands of oil can make a difference. My 2002 pickup will lose oil when running Mobil 1, switched back to my favorite, Valvoline, and it quit completly. Mileage on engine will play a factor. A compression and leakdown test will id any problems and where to look. Start checking every two weeks, getting two quarts low is pushing things.

 

Roger That!!, will do and report findings.

 

How many miles are on it?If you install new heads on and old bottom end the fresh new valves will rise the compression and if the rings are weak it will make it burn even more oil.

 

Cam/Pistons and heads are the last components on the engine to be touched by me, all other major components have been replaced. All I know about the engine is that it's 37 years old.