JB makes a great product, but doesn't seem to answer the phone or email. However, if you call and leave a message he will call you back every time. The product was top notch as well, I'm happy I went this direction.
I think I used the 1205 kit when I did mine. 89 241C with a mechanical speedo. As long as you have good snap ring pliers the 241 is actually fun to work on. The most challenging part for me was putting the case halves together while making sure the oil pump and tube stayed in place. I have some info on my build thread covering some of the bits related to this. I used a 1310 non cv yoke output on the front.