You should be fine with a 75 shot. It might not hurt to get a better fuel pump and such. I'm running an 80 shot, with no problems. Don't have any knowledge on the ZEX kit sorry.
Steve Black 97 GS First time at track 16.231 @ 86.11 (Intake & Exhaust/ 17" rims) Best time- 14.154 @ 101.22 W/O N2O- 15.916 @ 88.98