Hi
Sorry, PM inbox is probably thousands over being full.
I swapped in my 350z for a GT4 a few years back. Love the GT4.
I did indeed take the spoiler risers out to lower the wing, it's just personal preference. The bonus is that the WRC risers sell really easily, think I got around £40 for mine on ebay and they needed a respray.
The best thing I ever did with this car was take it to Martin at MK Auto Repairs And Tuning https://www.facebook...4641634?fref=ts I'm real damned picky with garages after being burned a few times in the past with so called "amazing" recommended garages doing shoddy jobs. Now I drive from Coventry to Blackburn to get the car worked on, it's worth it. Let him know I sent you
Speaking from experience I'd take everything previous owners say as a guide to the car, not fact. Get everything they have told you confirmed first and then work from there. My car was running 300bhp when I got it, but only because of some Maplin style ECU mods that ended up killing my injectors and MAP sensor. I detuned mine right back after that was discovered and then I rebuilt from stock levels.
Originally I bought mine with forged internals, and some random bits modded here and there. Since then, due to the shoddy work of previous owners garages, I've replaced most of the engine. I'm not too concerned about it as now I know it has been meticulously put together by Martin. I basically have a factory fresh engine. I bought some fresh forged pistons too as the bore in my engine was stupidly large for stock sized forged pistons it had, I stepped up to the next size piston and we bored the block to match perfectly.
Turbo wise, it depends on what you want out of her. Personally I decided on 350BHP as you can get a refurb of your stock turbo with hybrid internals. The hybrid actually gives you a better spool time and wider power band than the stock as it's ~15 years newer. If you go bigger than 350BHP it starts to get on the laggy side. There are plenty of guys running bigger turbos pushing out 400~450 no problem, but it delivers it in such a different way. You completely miss out on low down power, and when you do get power it is all in one lump and over very quickly leaving you changing gear rather often. Again, all personal preference though.
I happily pay the gt4oc.net membership as the guys on there really know their stuff. They also have their own version of Ebay which you can view without membership.