We have been using an M45 in our ProRally car for severals years. The O/D adds weight and complexity you don't need. Biggest problem with either is the gap between 2nd and 3rd. We solved that with a Quaife close ratio geatset but that is another story.

Skip
'93 850GLT
'89 765T
'83 242T Flathood

My understanding is that the M45 is essentially the same gearbox, sans the overdrive, and with a different output shaft. The overdrives are notoriously flakey on high mileage cars (usually electrical problems with the relay and/or solenoid), but the car is perfectly drivable even if the OD is non functional. In fact, a later (post-'82) M46 might be more desirable as it has a shorter first gear. I think that for your purposes, an automatic car would be ideal, because they had the shortest rear axle ratios. Then swap in M45/M46 and you're set.

Disabled or not, the OD's will cause you headaches. So I'd say go for a M45.

Or, if they allow swaps to other transmissions. John Parker at www.v-performance.com are working on T5 transmission adapters.

Doug
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Sacramento VCOA President, (sacvolvo@hotmail.com) Admin @ clubvolvo.com 2001 S60 2.4t w/17' Amalthea & Premium package 82 242t 5spd (Offical Project Car!) w/ With more parts than I can list, 85 244ti~ Parts car