Nissan Skyline GT-R , R32, R33, R34

Important things like changing out the turbos, fuel filter and the plugs as soon as you get it. 

"...The issues with having the coils in the valley of the head, and covered, is they cook. I personally think that about 40% of peoples issues with misfires, are the coil harness cooking in the valley. 20% is probably spark leaking from the boot. 10% the plug. 10% the coil. 20% the ignitor, ecu, or CAS. It takes about 5000 less volts to arc a iridium plug vs a copper plug. So generally an iridium plug will help your ignition system last longer, fire easier."
"...Same as a 1996 Infiniti J30. Its a good idea to change it when you get the car. Its almost the same as a 300ZX filter, but the outlet has a 90 degree bend on the actual filter."
"...Fuel Pump - 195 L/hr . If its 25 years old, it might be a good idea to change it Nismo replacement is 276 l/hr"
"...Turbos - Above about 1.1 bar the stock ceramic exhaust wheels have a tendency to break the exhaust wheel off. People have gone low 12's, high 11's on the stock ceramic turbos, but not for long. Luckily the NISMO R32's came stock with all metal turbos."

https://www.gtrusablog.com/2010/05/real-basics-nissan-skyline-gt-r-r32-r33.html