125 or 150 N2O shot? NOS/N2O Express?

Thanks Skyman. Going all motor's really cool. I've been thinking about going w/ a dry kit (from what I've read on this site). What upgrades should I do before the N2O goes in if any? I've been thinking 1.6 alum rr's, up/lwr rear ctrl arms, MAC 3" exhaust off 1 3/4" long tubes......how about tranny/clutch (or should I wait till I roast them both )?

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'90 LX 5.0; 12K original miles (no sh*&); 3.55 gears; pulleys;Edelbrock Performer Heads; BBK shorties; MSD 6AL box w/ blaster 2 coil; Motorsport E303 cam; Pro-M 75mm MAF; BBK 70mm TB; Eibach spring kit; Southside welded subs; K&N cone filter charger; Hurst shifter; fiberglass turbo hood; A/C-less; rear seat-less; cat-less; 2 chamber Flos; Corbeau racing seats (fronts);
30# injectors; JMS Chip; 190 lb fp; TFS track heat Intake (12.299 @ 113)