Trying to turbo an NA 300zx is hard - especially one from the 90's. Not only do you have to deal with twin turbo's, and fitting them in under the hood, but you need to find a computer that is programmed for a turbo engine for a similar year - and sometimes the exact year you are working on. I have a 86 300zx NA that I've had for almost a decade and will be looking to sell it in the near future. For my year Z, Nissan moved the alternator to the other side of the engine if it was a turbo model - so I'd need to find that bracket to hang the alternator on the opposite side of the engine if I wanted to turbo mine. Also, the Compression Ratio was different on the NA vs Turbo motors. Lots of people have turbo'd an NA engine without any troubles as Nissan only used about 8 - 10 PSI boost. Any higher than that and you might have issues. The 90's Z's are the next generation Z's from mine - the 85 - 87 Z's were called the Z31 and the 88 and up were called a Z32 because Nissan changed a lot. Namely the turbo models got twin turbo's - one for each side of the engine as well as different suspension and body panels to make them more rounder as opposed to the square'd body panels of the 80's. Increasing the value, that's kinda subjective. Check out the forums on zcar.com - there is where I've found a lot of good information for my Z on aftermarket parts if you want to change out the shocks or springs or lower it. For the Z cars, I've seen it said from many people = Stand back and Throw money at the car, and I've found that out to be true. Fun car to drive, but parts are not cheap - like our Mopars! Best of luck to you.
