It's really all up to you and what you're trying to do, and what you can do. There is nothing bolt in and there are no kits. I can try to help with what I've done and seen but if you're headed a different direction you'll have to do a lot of your own thinking, and don't forget to let us know what you figure out.
I like the P30 axle and the hard to find 22.5" wheels. Pretty sure any axle you find other than original or older is going to be to wide. So if you find a more suitable modern swap please tell us about it!
Your tape measure is your best friend.
Grigg
