Originally Posted by shepherd57
I have the 545 in my Isuzu powered 32.5 it is a good trans but it has no lockup converter and no overdrive. I am thinking about putting in an Allison 5 speed with the lockup converter. It will bolt right in and will need a stand alone wiring harness and Allison TCM to make it all work
In your application I'd stay with the 545 and change the rear end gear to get the same effect as an overdrive. The 545 has so many clutches/plates it is better than a 'lock up' convertor.
I should/would have done that except I increased the input torque well above the max input for the 545