Hi you are looking at a 7" 3.9 gripper diff (race spec ramp angles). I also have 3.9 drop down gear and new shortened chain. I bought the diff brand new from BARA last year and its done one race season. I sent the diff back to BARA for a check up at xmas and he will confirm the diff is in perfect condition. Im needing £1000 for the diff, drop gear & chain. Any questions just ask.