I believe you would only have to upgrade the valve springs if you go with a 11.5mm -12.5mm lift cam!
------------------
http://members8.clubphoto.com/louis419830/439477/guest.phtml
Louis Anaya 1992 Sentra SE-R
349.6 hp & 301.9 ft/lb @ 19 psi, 12.0 @ 118.77, Bluebird SR20DET, T3/T04E, Deltagate Wastegate, FMAX Manifold, RevHard FMIC, JWT S3 Cams, JWT Ported & Polished Head, 1996 200SX SE-R Welded & Cyro Treated Tranny, ACT Xtreme P/PL & 6 Puck Disc, Cobra MAF, JWT ECU w/ 4 Bar Fuel Program, MSD 50lb/hr Injectors, JWT Fuel Rail, 300ZXTT Fuel Pump, AeroMotive Adjustable Fuel Pressure Regulator, Greddy Type "R" BOV, Greddy Profec B, Greddy Boost & EGT Guages, UR 4 Pulley Kit, Powerslot Rotors, Axxis MM Brake Pads, ES Motor Mounts, Topspeed Short Shifter, Momo Cobra Shift Knob, Autometer Shift Light, Fiber Images Carbon Fiber Hood, KYB AGX Struts, GC Coilovers (350F/600R)& 17x7 White Tenzo Shu-4's w/ Yokohama 205/40/ZR17 Tires (Street), 13x7.5 White Lenso VPD's w/ Mickey Thompson 24.5x8x13 Slicks(Drag)