Offenhauser 5272 GM Manual Trans to Flathead V8 Adapter, Ford Clutch

Get more performance and driveability out of your Ford Flathead V8 by hooking it up to a GM manual transmission! This adapter allows you to easily install a GM 3-, 4-, 5-, or even Early T-5 GM-style 5-speed manual transmissions (Not Compatible With: later 1993+ S10/NV1500 units) behind your 1932-1948 Ford or 1939-1950 Mercury Flathead V8 engine.

Permits use of your Ford clutch release shaft, fork and throwout bearing. Throwout bearing must be used with a Long-style pressure plate.

• Fits 1932–48 Ford, 1939–50 Mercury Flathead V8s
• 1948 Trucks and 1949–53 Ford/Mercury need OEM 3" adapter bellhousing
• Not compatible with Canadian Mercury “French block” engines - verify block type before purchase.
• Adapts GM 3-speed, 4-speed, 5-speed, or Early T-5 GM-style 5-speed manual transmissions (Not Compatible With: later 1993+ S10/NV1500 units) 
• Uses stock Ford clutch release shaft, fork, and throwout bearing
• Compatible only with 3-finger Long-style pressure plates and stock-style throwout bearings.
• Diaphragm-style pressure plates will not work.
• Includes pilot bushing adapter

NOTE - If you are still using the stock rear axle assembly, an open-drive conversion will be required. Depending on the year and style of your differential, Speedway Motors offers several kits to assist with this conversion:

• Part # 919-1105 – 1935–48 Ford 6-Spline V8 Banjo Rear End Open Drive Conversion Kit (fits ’35–’48 rear axles with common 6-spline pinions)
• Part # 919-1106 – 1935–48 Ford 10-Spline V8 Open Drive Conversion Kit (fits ’35–’48 rear axles with common 10-spline pinions)
• Part # 919-1111 – 1928–31 Ford Model A Open-Drive Driveshaft Conversion Kit

Once the conversion is complete, a custom driveshaft will need to be installed. Speedway Motors offers Part # 910-383, a Universal Steel Custom Length Driveshaft Kit with a 3-inch OD. Other diameter and material options are also available to accommodate a wide range of applications. 

• 1932–1948 Ford Flathead V8
• 1939–1950 Mercury Flathead V8

NOT COMPATIBLE with Canadian Mercury “French block” engines

Installation Notes (PDF)

• 1" thick mounting flange
• Adapter is 3-7/8" thick front-to-back
• Bellhousing mount holes are drilled for 3/8" bolts
• Transmission mounting holes are tapped 7/16-14
• 8-1/4" center-to center top bolt holes
• 9-1/8" center-to-center bottom bolt holes
• 4-7/8" center-to-center bottom bolt to top bolt, either side
• Pilot bushing adapter I.D. is 0.590", .660" O.D., and length is .790"