Hooked up the fuel pressure regulator what was unhooked and capped for some reason. Naturally aspirated SR20DE, aftermarket purple (?) pressure regulator, unhooked. The car runs a hell of a lot better now, albiet without the little "bump" in power between 4000 and 5000rpm that was there with the FPR unhooked. Weird.
Also, one of the previous owners upgraded all the engine grounds and re-ground the MAF to the intake manifold. Also found a Haynes manual with receipts for axles and a clutch dated last year, as well as an Energy Suspension poly shifter bushing waiting to be installed.