Ok - my gt4 hade 196 thousand on the clock when i biought it
its a 1990 model
so far bar replacing wear items like exhausts + suspension to better performance ones the only problem ive had with the high KMs motor is a blown headgasket ..
note its been run at 14psi for most of its life, so head gasket was inevitable ( stock ones only rreally meant to handle 10PSI )
mechanically they are toiugh as nails - GB's and diffs are VERY strong - the motors are tough + overall they are very sound
This is where you get your weight - they dont make GT4 gearboxes out of glass!
outside of that ive had normal wear in the syncros , and a clutch replaced by the previous owner , she leaks no fluids , and bar head gasket has been trouble free
budget 14K for a good one + another 6 for the inevitable mods youll want to do if its stock