All of them has LSD
Motorwise i wont recommend you to tamper with it if is running good the g54b is a temperamental powerplant that dont like to rev high, in order to do so you need a solid lifter valvetrain setup and a custom cam, then change the poor EFI system for a 4 injector setup, but when you get to that point you figure out u spend more than u want and find out you could do way better with an LS 5.3 GM engine with a turbo and spend less, at that point you will be pissed off stay away from the MEGA SHIT ECU engine management, by the time you finish and is working properly you spend more than buying a Haltech, fueltech, AEM or microtech brand real ECU system that gives you years of trouble free service without head aches,

It is a nice car and one of the best platforms from the 80's Japanese sports cars if not the best, i have been there and hade like 9 of them all the way up to 450 whp and low 10 seconds 1/4 mile E.T.'s on them,

So my advise is get yourself a nice 5 to $700 yukon or tahoe LS based 5.3 V8 a good size turbo and injectors, a good Fueltech ft350 ecu and a nice stick shift trany for it while you still got it in running condition and when you got everything go for the swap u wont be disappointed and with more power with less money you can get!