Need HELP bad! Daily driver pony on last leg....

This all started by me blowing up my 300,000 mile original 86 motor , I replaced it with a used motor out of a MARK 7. It was running perfectly then one morning I start it up & it has a dead hole.

Used a boroscope to check it out (cyl 6) & the piston /cyl wall looks to be in good shape. Did a dry compression check I got 25 psi Then I put oil in it & got 35psi. All the other cylinders had good compression. So I yanked a valve cover & made sure the valves weren't binding. The springs/ valves/ pushrods were all in decent shape but I have a consistent rattle sound sounds like a motor when you're lugging it in a high gear at low RPM.

Now today on the way to work it started smoking like the car on spy hunter.
So I took off the filler cap & was waiting to feel a whole crap load of blow by, but to my suprise & total confusion I have VACUUM!!! Very slight but I have vacuum... I took a paper towel & wiped inside the tail pipe & there is ALOT of oil in the exhuast. So then I check oil level & all my oil is gone...

Can someone shed some light on all of this!!!

THANKS
Mike

I did see a couple bubles of something not sure it it was coolant though... it wasn't signifigant enough to identify.

There's no oil on the dip stick now & there were oil droplets blowing out of the tail pipe.It's ALOT of oil....

Thanks
Mike

ftw?

BTW would I have blow by if the rings collapsed?