The MGA five-speed conversion kit stocked by MGOC Spares was developed by Hi-Gear Engineering and is designed around the Ford Type 9 gearbox. The kit adds a selectable fifth gear under the control of a clutch and gear lever, while also giving synchromesh on all forward gears including first, an advantage over the original MGA gearbox, where first gear is non-synchromesh on all production variants. The kit is specifically aimed at owners of non-overdrive MGAs, and the Ford Type 9 gearbox at its heart is a well-established classic-car transmission upgrade widely used across the UK classic car sector.
Hi-Gear Engineering kit, what it does
The kit offers four principal benefits to the owner of a non-overdrive MGA. First, relaxed motorway cruising at significantly lower rpm in the new fifth gear compared to the standard 1:1 fourth gear fitted at the factory. Second, improved fuel economy at cruising speed as a consequence of the lower rpm. Third, slick gear changes with synchromesh on all gears, including a synchromesh first gear not available on any factory MGA gearbox.
Fourth, a 10% higher top gear for more responsive acceleration and safer overtaking, compared with running in direct-drive fourth on a standard MGA. These benefits are marketed by Hi-Gear as the combined case for the conversion.
Kit contents
The Hi-Gear five-speed conversion kit comprises an alloy bellhousing, a propshaft matched to the Ford Type 9 gearbox dimensions, a gearbox cross member, a speedometer cable matched to the new gearbox output, the necessary fixings, and comprehensive instructions for a DIY installation. Parts may vary depending on the specific MGA model being converted.
Ford Type 9 gearbox, supplied separately
The Ford Type 9 gearbox itself is supplied separately from the Hi-Gear kit and is not included in the kit price or kit parts list. Customers ordering the kit therefore need to source the Ford Type 9 gearbox as a separate order, either from MGOC Spares where it is available, or from a suitable supplier.
This is an important ordering point: the kit on its own does not provide the complete installation unless the gearbox is also obtained. The conversion works around a standard Ford Type 9 four- or five-speed unit in its factory form, adapted to the MGA engine installation through the alloy bellhousing.
MGB engine conversions, optional backplate
A specific scenario for MGA owners who have fitted an MGB B-series engine to their car: because the MGB B-series bellhousing interface differs from the MGA B-series, an optional backplate is available separately to adapt the Hi-Gear kit to an MGA-bodied car that is running an MGB engine. This is a specific component not included in the standard kit; it should be ordered as an additional item when the car's engine has been swapped to an MGB unit.
Ordering considerations
The Hi-Gear Ford Type 9 five-speed conversion kit is supplied without the Ford Type 9 gearbox itself, which must be ordered separately. For standard MGA cars running their original MGA B-series engine, the kit as supplied is correct. For MGA cars that have been re-engined with an MGB B-series unit, the optional MGB-engine backplate should be ordered alongside the kit to provide the correct bellhousing interface. The specific parts list in any given kit may vary depending on the MGA model being converted, and ordering should confirm exactly what is included for the target car.
Instructions supplied with the kit cover a DIY installation; the installation is straightforward in the sense that all the required components (other than the gearbox itself) are included in the kit, but it is not a quick job and requires removal of the original gearbox, propshaft and cross member.