I have a 67 Chevy c-20 camper special with a remanufactured 85 350. I would like to swap out the engine for a new crate motor( preferebly a GM 350 long block) as well as replace the tranny. Its a 4 on the floor, and geared for towing. I would like to be able to drive on the freeway, since this is my daily driver.I'm reading as many of your articles as well as some others, but am not sure what combinations would work well with each other. My goal is to make it geared for southern california freeways, have enough power to get some speeding tickets, and in general have something reliable. I can turn a wrench, but am not the grease monkey I'd like to be. Any info, tips, or suggestions would be greatly appreciated. One last thought, this is obviously going to affect the rear end( gearing for freeway )is there a good pre-fabbed rear end out there, or is it better to just re-gear what I have now? I do have a budget in mind, but would be willing to fork out a little more for quality.  

You could swap the rearend for something similar but has the gear ratio you are looking for. Chose something in the 3.0:1 ratio. I like the idea of swapping gears in my setup that way I know I have the good stuff inside. Ring a pinion gears cost $150. You may have to swap the carrier if your original has gears with a numerical number over 3.73:1. That will cost $400 but you can get a used open (non-posi) cheap off ebay. A shop will charge you $200 to set up the rearend. Go with a quality shop.
As for the tranny, 700r4 is the ONLY choice.
Your 85 350 should work fine as long as its running good.
Good luck with your project and post your results here for us all to enjoy.  

What 68 chop top said on the gears! As for ditching the 350 in the truck for a new 350 crate motor, my only question is why? that's like swapping apples for apples. the motor you have in there would be fine to use, if its more power you're after spend the money you were going to spend on a crate motor on speed parts. If you want a fresh motor than work with someone to rebuld that motor for you and install the speed parts you want in it. A good shop to use here in So Cal, in terms of getting that motor built, is Vrbancic Brothers in Ontario. give them a call, they'll be able to help.  

The reason for the crate motor, is the engine in the truck now has a prominant rod knock, and needs to be rebuilt. Time wise, I would assume a crate engine from Jegs, or summit would be delivered in a week or so. I also don't have a way to get the original motor out to ontario. Since this is my daily driver, I now have to ride the bus and when it works out, have my old lady drop me off at work.... this has been pretty humbling. I would like to drop in a crate motor, without the top end parts( since i have them on the existing engine ) just to get it running and be worry free. Once the truck is running again, I would really like to use the old engine as a power project some time down the road. Is it feasable time wise for a rebuild from the shop you mentioned? Here's a stupid question, that I hope you can answer for me. Right now the existing engine is a 2-bolt main. Would it be possible for a new crate engine to be a 4-bolt, without getting too involved? I've heard that a 2-bolt main is stronger, and can be made into a 4-bolt. What would the pros and cons of replacing with the same 2-bolt, versus putting in a 4-bolt? I appreciate the reply, as well as the info on the shop in ontario, I'll look into it.