MGB 5-Speed Kit

Kit converts the 1968-1980 MGB to a quiet, durable, all synchronized, overdrive 5 speed transmission. The transmission used in this conversion is from a Datsun 280Z. This gearbox was used behind a powerful, fuel injected 2.8 litre engine in the Datsun, and was durable in that service. Yet, it is 23 pounds lighter than the standard MGB 4 speed. It is 0.864 ratio in fifth for quiet, reasonable RPM cruising.

The conversion requires no modification to the MGB chassis, except to the bolt-in rear crossmember. No modifications are required to the engine.

The kit consists of:

  • A billet aluminum rear engine plate with a new crankshaft seal, to replace the original steel plate.
  • A modified flywheel, which has been modestly lightened, faced and balanced, with a new flywheel ring gear installed. (Exchange for your MGB flywheel.)
  • A new clutch disc that matches the standard MGB pressure plate.
  • A rear transmission mount bracket.
  • A complete new driveshaft with u-joint.
  • A speedometer angle ratio adapter and new speedometer cable to correct speedometer reading.
  • A clutch alignment tool.
  • All fittings and fasteners required for installation.
  • Installation instructions, with color photos for clarity. Instructions include phone number to call if you need technical assistance. Included is a parts list of standard replacement parts that can be purchased locally, should you ever need them (clutch disc, throwout bearing, etc.).
  • A pilot bushing.
  • A billet aluminum slave cylinder, braided steel, Teflon lined hose, fitting, attaching bolts and push rod.


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