7.25" Gear change HELP

I have a 66 Dart with an orginal open 7.25" 2.93 axle. I purchased a 3.55 Motive brand ring and pinion set that they spec for 63-up Dart. There are 2 problems:
1) The pinion nut/threaded end is bigger on the new pinion (needs a bigger nut)
2) The pinion appears to be a crush sleeve style, not the shim style that the original was. The front bearing shoulder is machined much deeper on the new pinion.

I plan to order Motive's install kit so get what I need... The question is is that they show 2 kits, one is spec'd for the older D/P/Chrysler and the other is spec'd for Dakotas. Which one do I order? I don't know if I need the newer Dakota set to match the R&P I have or if I should order the older application. (I don't want to end up with an install kit full of shims only)

Please help, and thanks in advance.