A used transmission I purchased will not shift into overdrive it just lunges at around 60mph, and will not go any faster because it won't shift up, shifts fine up and down in all other gears, fluid and level is fine, solenoids are new, anyone got an idea?

There are a few ideas in the link, but you probably need a transmission specialist.

https://www.google.com/search?q=1999+GMC+Yukon+2WD.+Transmission+won%27t+shift+into+overdrive

..

Should be in overdrive & converter locked
at 42mph or about-- unless your flooring the gas

Internal Solenoid Problem or Valve Body Dirty

Can you count the number of shifts ?
2nd speed at 10 - 3rd speed at 20 - lockup and overdrive at 40 ?
Normal RPM for most cars is around 2000 at 60mph.

THAT IS THE OVERDRIVE IN THE TRANSMISSION
THE CAR MIGHT NOT WANT TO SHIFT TO HIGH GEAR OR OVERDRIVE SOME OF THESE CARS USE THE COMPUTER TO SHIFT IT TO OVERDRIVE AFTER IT GETS WARM THE THERMASTAT PLAYS A ROLL IN THAT WHEN THE ENGINE IS WARM THE LOOP IN THE COMPUTER CLOSES AND THE CAR WILL SHIFT TO HIGH/ OF THAT WON,T FIX IT THEN THE COMPUTER IS AT FAULT OR THE SENSOR IN THE TRANSMISSION IS BAD

is it shifting into overdrive?, auto or standard trans, at 60mph most vehicles with overdrive are at about 1800 to 2200 rpms...

has someone lowered your final drive axle gear ratio...?

on the older style blazers the fan clutches did fail and would often be misdiagnosed as shifting problems as the clutch engaged and disengaged.... also a hard 1-2 shift can be due to your vehicle storing a transmission fault code in the ecm... some transmission fault codes will put the transmission into a fail safe or limp mode in which it engages high line pressure .... this can cause your hard 1-2 shift and will feel normal most of the time other than that. high mileage on the transmission fluid may also require it to be flushed and have the filter kit replaced

it might have been a former rental car that means it could have govenor on it.but by it being an 87 it might just need to have tune up

a solenoid problem if its an automatic transmission,if its a manual(with clutch)then its probably the syncros bad