jeep grand cherokee 5.2 as donator for my dart gt -65, what gearbox should i use?

No 4-wheel drive in my Dart, hehe.
Original, and for the moment, is a 273 v8 mounted. Where can I get this "torque converter register bushing" for the original gearbox? Or is it something that has to be manufactured?

I also have a ford 8.8 rear axel with LSD, and if I remember correctly, it's not as wide as the jeep axle. I'll have to measure and check. An additional advantage of such an axle replacement is that I get rear disc brakes, then I only need to buy a kit for the front brakes.

Edit: Have read about the 8.8 axle now, it's sounds like it's a good alternative.
And found some picture of the bushing for the converter, looks that it something that can be manufactured after some measurements. But still interested if it's possible to by somewhere.