hello everyone!
im new to 300zx's ive had a few RHD turbo cars and know a few things but apparently not enough lol. The car im lookin at is 1990 5 spd t tops VG30DETT 60000 km. Body is decent little rust under tail light and bad bondo job along with clear coat chip under rear windows. Car runs and drives but under boost blows blue smoke and its quite embaressing, but the guy only wants 2500$ and i dont want to turn it down. Advice is really appreciated thanks in advance for your help!

Also the illumination fuse keeps blowing (dash, headlights,tail lights only high beams work, i think its a shorting stereo wire from the crap job haha) doesnt leak any oil and doesnt tick doesnt overheat it is NOT head gasket or valves