This won't be easy. Probably the best thing to do would be to hit the junkyard and try to find a 2wd model. Otherwise, your best bet is to just leave the transfer case attached. It's a lot of extra luggage to pack around though. Glad you are putting in a 302. Although they are basically the same, I've never liked the way the 351 runs. It's just gutless. The top end is all wrong. The 302 shorter stroke feels a lot better when you pour on the throttle. Good luck.

This ****** will not work from 4 wheel to 2 wheel
You will have to change the inner shaft and add a tail housing

You can convert it, the mounting studs should be under the dash for the pedals and such, just have to fasten it in place. The 4×4 will have a different output tailshaft housing due to the transfer case mounting. If both are AODE transmissions, you will have to find a 2 wheel drive tailshaft housing to mount the 4×4 manual into the automatic truck, and also use the flywheel and driveshaft from the manual truck. The only thing you are missing from my point of view is the extension housing for the transmission to mount the 4×4 trans to a 2wd truck.