well what shock are you using? are you useing the shock for the 4 inch lift? or one for the amount of lift you have with the 5.5 coil? as long as you can align the TTB properly you can use a longer coil. the stiff ride can be caused by having too short of a shock on it, or by having a coil that is too stiff and designed for a different vehicle or combination of options. if you have a 2wd truck with a reg cab and a 4cyl then it is A LOT lighter than an extended cab 4.0L 4x4 and some companies actually sell different springs based on the setup of the vehicle. my first guess however would be a shock that is too short. a little bit more information about your truck and the lift and components that you are using would be very helpful in answering questions.
'94 2.3L, M5OD, BW1354 manual, 4x4, 31x10.5 BFG A/Ts, 15x8 AR Chamber teflon rims, 7.5 4.10 lock-right w/disks, D44 SAS 4.10 aussie-locker, duff traction bars, electric fans, spintech muffler, duff poly body mount bushings, Lightforce RMDL140's, cobra 18wxst II, herculined floor, 375,XXX
'87 camaro 305 carbed (needs engine)
'92 subaru legacy 2.2L Turbo (needs tranny)
TRS Tech Support Staff