I bought a 1961 Ford unibody that has a 1976 Mustang 302 engine and 3 speed automatic transmission. I would like to replace it with a 4 speed automatic. Any help would be appreciated.
The AOD is your best bet, unless you want to start messing around with electronic shift versions (there are controllers available for the AOD-E/4R70W, not sure about the A4LD). Some of these may have had lock-up torque converters, but you can just leave that unplugged if that's the case (they run off the ECM, which a '76 302 ain't got). You'll need one that has the correct bellhousing pattern, which is known as the "Late Windsor". More info in these 2 links. Cross-reference the models at the top of the 1st link with the engines in the 2nd link (right-hand column only), and if it has a 4 speed auto, it should be an AOD.
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