I'm thinking of the tcm-2000 transmission controller. Not cheap at around 700 quid but seems like a very versatile piece of kit. I was going to fit my np231 to the 545, if it'll fit, i think it's just a question of spline count.
The bigger problem as far as I can see is the torque converter. My engine has the ring gauge on the torque converter but the 545 has it on the flex plate. Some modification needed there I think.
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