The Quaife limited slip differential is the most significant drivetrain upgrade available for the MGC, providing proportional torque distribution to both rear wheels under all driving conditions. The improvement in traction and cornering stability is immediately noticeable and transforms the car's behaviour on wet roads and during spirited driving.
Five-Speed Gearbox Conversion
A five-speed gearbox conversion replaces the original four-speed (plus optional overdrive) gearbox with a modern five-speed unit, providing closer ratios, a more usable gear spread, and a genuine fifth-gear overdrive ratio for relaxed high-speed cruising. This conversion addresses one of the MGC's most commonly cited limitations, the wide gap between third and top gear in the standard box, and the relatively high cruising revs even with overdrive engaged. The conversion is a significant undertaking but the result is a more flexible and enjoyable car for modern road use.
Axle Ratio Changes
For owners seeking to change the rear axle ratio, either to improve acceleration (higher numerical ratio) or to reduce cruising revs (lower numerical ratio), reconditioned axle assemblies and individual crown wheel and pinion sets are available in all three original ratios. The 3.7:1 ratio is a popular retrofit for early overdrive cars that were originally fitted with 3.307:1, as it significantly improves acceleration and drivability.