Is there a way to know if an engine was overheated if it's not running?
 

I've just recently aquired an 86 GXL and the PO swapped an s4 turbo motor into it at one time. he's sold the original exhaust before he sold me to the car so until i can replace the exhaust system I'm unable start the it and check that way. my question is are there any real tell tale signs visually if the motor was overheated? I've checked the fluids and it seems the coolant has been drained since it was sittings for 8 months.

Why not start it? screw the neighbors lol And I hope you got a steal for a non running car and unsure if that motor is good...

there usually is not a tell tail sign, unless u fill it with coolant, turn it over by hand and see a a bunch of coolant in the rotor housing!
but a small coolent seal leak wont show until its running and burning or over pressurizing the system

if you can source a downpipe you could start the car and see.

Fill the coolant and rent a pressure tester. It will either hold pressure, leak coolant out of the engine or leak into the engine.

All sound like good ideas. I'll start with the pressure check. Sounds doable