I used to drive a F650 with a 6BT (that's right, Ford knew the PunyJoke couldn't cut it in a medium duty truck) but it was a 26k hydraulic brake truck. I knew they used them in some heavier airbrake trucks also but didn't know they went up to 50k trucks. I don't imagine those trucks were fun to drive fully loaded. I had that F650 up to 40k a couple of times and wasn't sure if it would make a couple of hills coming back.
I know that the 4-53T was used in some 80k applications, but I am sure that they were not fun either. That would be better for a 6-71, 8-71, or 8-92 for sure. The 8-92T was a beast, but that would never fit in a pickup. I only got to drive a couple of these in worn out trucks when I first got my CDL and was not impressed. I liked the later 12.7 liter 60 series better. But for a pickup I would choose the 5.9 L 12V over any other diesel past or present. But I also am no diesel mechanic that can squeeze 500 HP out of a 6 liter engine either. 500 HP out of a gas engine is easy, but it would lack the fuel economy and torque that a diesel could provide.
Yes they were both dogs in a medium duty truck, but when Dodge put the Cummins in a pickup, they basically started the diesel pickup market. Again I am not a diesel mechanic but couldn't you get you power without electronics? The best thing about the older engines is the simple design that doesn't need a computer to run.