I have a 52 Chevy 1/2 ton and did a similar thing with the following differences: The saginaw 4 speed may fit very nicely behind the 51 216 ci bellhousing mine did on the 52 even with a 235 bolted to it. Try to find yourself a 2 grove transmission input shaft saginaw. You will need to keep the 51 bellhousing because of the rear support mounts. The 2 grove may be hard to find, however a 3 will do ok. You also say or imply that this kit will allow you to use your orig chevy 4.11:1 rear. You will be gaining nothing really, because in the end you still be 1:1 different transmission or not. Recommend that you consider saving some of that 400+dollors and get a junk yard opendrive rear end, GM of course. Stay away from the **** 9's as they take 1 to 2% more HP to turn over because the pinion sits lower. However put in a **** 9 if you will be someday putting in a big v8. Anyway the GM rears you can get all day for $100. and you can pick the gear ratio. The ideal ratio in my view is a 3.08:1. This will allow you to run on the interstate and around town real nice at 60+mph. Some say the 3.55:1 are ideal, but to me too high rpm with the 6 cyl. I'm very familiar with the Patricks products and recommend his Saginaw shifter. Its a Hurst Comp shifter with a mounting plate that allows it to be moved up to use with your orig seat. If you are not confortable with tearing into the trans to check it out take to a local trans guy. The 52 chevy 1/2 ton rear measurements were 56+1/2" (inside flange to flange). Take your own measurements and go shopping for a similar rear from a leaf spring rear. It doesn't need to be exact. Just be sure it fit inside the rear fenders and looks ok. You'll know. Just measure from the same location. Nova rears, Olds rear, 92 up chevy truck will be close. Thats ok, you'll have to change the spring purch location and set the pinion angle, not as hard as everyone makes it. And you will need a new driveshaft about $150. If you would like to contact me Chief post a private message thru this forum. Good luck to you.