If you must.... And don't get me wrong. I do like automatics.

I am not a fan of the BW35 in 140s. It's a heavy car, and a pretty weak transmission. I bought a low mileage (117k original) '70 145 with the BW35. It worked fine when I got it, but fully intended to convert to 4 speed overdrive. So, I was admittedly abusive.

In the two weeks I drove that car, with the worn out engine, I killed the transmission.

I'd think real seriously about going with a AW71. Sure, you'll have to modify the bell housing to deal with the slanted B23/B230. But you gain better gearing, a floor mounted shifter (much easier to install, I'd think, than the column mounted shift), You can keep your GT gauges, and a locking torque converter..

Difficulties might include a custom crossmember, custom driveshaft, maybe the need to enlarge the tranny tunnel. I think those troubles would be worth the effort to have a much better car in the end.

That said... never having done it, I really can't say how tough it would be.
I'd think a donor 240 would sure be easier to find than a donor 140, which is what you'd need...


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-Matt I ♥ my ♂