I had the running 250 from my car on here and got down to $50 and still couldn't sell it. I ended up throwing it in the scrap pile
Ever look at the intake manifold for the reason it was burning oil? I did a cam swap on the 351w I once had in my F100 and after starting it up it starting smoking and burning a lot of oil once warm. I knew the bottom end was in great shape so I didn't give up on it. Turned out after every kind of test I did on it and changing everything I could think of that the number 5 area of the intake was leaking and somehow allowing the intake to suck oil into the intake port. I might not have been as bad as yours is but smoke bad out of one side of the exhaust and was using oil. Didn't use a lot because I didn't drive it like that. I changed the intake gasket and all was fine after that I never could see any breaks in the intake and never knew exactly why it was doing it clint
I had guessed that there was a little rust in the cylinders since the motor was sitting for so long, but i was stupid 5 months ago. Now im paying for it, but atleast it will be right. Also when i did the head swap, i also suspected that the bottom end wouldnt last too much longer.