Got the 4.30's installed in the 98 LSC today. Motive IX (lightweight gears), poly diff bushings, trac-loc rebuilt to 03/04 Cobra spec with carbon clutches (3x as strong as regular trac-loc clutch material). Speedo is dead on, no need for speedo gear for the tranny with the gen 2. I haven't gone WOT throttle yet but the gears bring a smile to my face. I had the 4.30's on my 95 LSC and they cut my 1/4 mile time by around 6 tenths. BTW, stock driveshaft, doesn't begin to vibrate until 80 mph which I can deal with for now. Very happy about that as well... my 95 LSC with the 4.30's vibrated starting around 60mph.