After a lot of headache asking for help, I have a r33 rb25det motor ( block number confirms) I got a rebuilt gearbox with changeover. Old gearbox had noisey bearings and crunchy 3/4 shifts, with a brief visual they looked the same. I upgraded from a exceedy sport tuff h/d clutch also has fitted a exceedy lightend flywheel to a NPC 300rwkw capable clutch for future mods, after fitting the new gearbox after elongating some bellhousing Bolts, slightly off compare to old mostly the bottom ones going through the backing plate.... there was excessive clearance between the clutch thrust bearing and touching the pressure plate.
clutch slave cylinder push rod wouldn’t fit, after using NPC guidance there was 24mm clearance between, which they’ve never heard of, after fitting a longer thrust retainer to remove the clearance down to 6mm the clutch wouldn’t fully disengage, in gear foot on clutch turning the tailshaft clutch could be heard dragging and had abit of resistence to turn, whilst driving it was crunchy
there was 10mm height difference on pressure plate clutch fingers when bolted to flywheel between clutches
after drivability problems I decided to play around with spacing the clutch fork pivot and decreasing clearance down to 4mm but the NPC clutch still was dragging, so I decided to fit the old exceedy clutch that was working (now has been sitting for awhile) I fitted all the original parts from the old gearbox thrust retainer, removed clutch pivot ball spacing, now this clutch wouldn’t disengage at all, so I’m at a loss help....
summary
rebuilt gearbox with new oem front plate where thrust retainer slides on
new clutch slave cylinder, bolt pattern one on top one on bottom
NPC 300rwkw clutch
exceedy lightend flywheel 2mm difference overall height difference to factory flywheel
apparent auto to manual converted
new clutch pedal box
everthing bolts up the same except for lower bellhousing bolts and starter motor needed to be elongated
