Allison AT545 in D300? Can it handle it?

[dustydog]

I'm amassing funds, time and parts to finally do a MAJOR overhaul, resto, build up on my Dodge. Looking for a school bus donor for permanent tranny and temporary 5.9 (plus to get my hands on the adaptor plate for tranny. I know that the tranny is pretty big but not excessive and the plasma cutter says it fits. My only concern is the power/tourqe rating for the Allison 545 seems lower than my target HP/TQ. I always thought when the time came to go full 'zoot' and try for the dyno tilting HP/TQ but #2 @ $5 ... maybe not so much but would still enjoy a good pull every once in a while. Any other suggestions for trans? Would really like a stick but it seems so much easier to use the AT545 or? Already have found a HUGE Dana 125 from an F-550 and the master cylinder to boot. I just want a reasonably hard running MECHANICALLY injected truck that can surprise the unknowing, last another 500,000 after rebuild and get decent mileage. I have that stupid 727ish 3spd. and still manage to get 15-17 MPH around town and have gotten as high as 24 on the highway if you keep your foot out of it and I'm empty which is pretty good for an auto with the aerodynamics of the 'Nimitz'.

 

[Garbage_Mechan]

AT 545 has 4 speeds, no overdrive, no lockup in the convertor and a kind of loose convertor. They were ok in some 160 hp trucks I had but a 190 hp Dt466 is a bad mate to it. Maybe if there is a tight convertor available, but frankly there are better. Problem is they are mostly all electronic.

 

[rhett]

at545

the at 545 is a fully mechanical unit, no electronics. as for the hp and torque rating, it is based on gross vehicle weight and usage. a tq converter with the proper stall may be available directly from allison trans. if not a custom unit could be built.

 

[typ4]

As said the issue is stall speed, get a convertor tightened up and the trans should handle the power. I would try the convertor that comes with it first then get one "tuned" accordingly.
Did a couple of these swaps in trucks and pushback tractors at work. Virtually no trouble if they remembered to release the park brake.