I recently found a exceptional clean 1974 Chevy Blazer that is completely stock with a 350, turbo 350 tranny and a np203 transfer case.  I plan on tearing it apart, putting a 4" lift with 33 or 35s, bore and stoking the 350 to a big block, putting in a 700r4 tranny with a 205 transfer case.  Would all of this fit very well, or would I run into problems with clearance, etc.? Thanks  

Well you cannot bore and stroke a 350 to a big block because a big block is a whole different engine. Next if you put 33 or 35 on it without regears axles you will toast 700R4 over time when it tries to use OD. Honestly if you put in some say 4.88 or 5.13 gears with 700R4 with a stock 350 in good order it will run pretty darn good. Gears are the key here more than engine size.  

I should've mentioned that of course I'd be re-gearing it.  Yeah, that tranny would be smoked if I left those high gears.  It's going to be seeing mostly sand dunes.  

If dunes are in the game plan, run as deep of axle gears as possible. Sand sucks a lot of power from wheels and you want a lot of mechanical advantage here. Your choice of a 700R4 is wise because it has a 30% od in it and it will hold up fine if axles are geared right and tranny is kept cool. Even a 5.38 only "looks" like about a 3.73 in OD as far as cruise RPM's and the 5.38/700R4 combo cruise at less RPM in top gear than a THM350 with 3.73's. Plus with 700R4 much deeper first gear together with deep axle gear you would find that you would not need low range near as much even in sand which is nice is you are getting some speed up.  

I haven't had any real experience in working on these blazers, but would there be a lot of issues in swaping the turbo 350 and 203 t-case with that 700r4 and a 205 t-case.  I'm concerned about the engine because I plan on using the 350 block.  I know that I'll need an adaptor to properly hook the tranny and t-case together, but is there something that I'm going to run into that will cause me to start pulling my hair out before I get too involved in this thing. Thanks.  

Well some might cry foul but I would suggest that you skip the 205 and go with NP208 which can be bolted directly to tranny and weighs a good bit less than a 700R4/205 combo and has the option of a deeper low range too. The 208 is not a bad Tcase and it sometimes gets a bad rap because wheelers use tall axle ratio/tire size combos and "live" in low range off road to try to overcome it and places a lot of extra strain on it. Gear axles properly and change fluid in it often  in sand duty and it will live a long time. One more tip, on 700R4, you want a 87 or later one. While the 700R4 got basically pretty solid by 85, in 87 it received on last tweak with a aux valve body to further improve shift quality. 84 and older 700R4 have 27 spline input shafts and are to be avoided completely. 85 on has a 30 spline input shaft.  

Thanks for the information.  I just think these things are awesome when set-up correctly, and also look good.  I wanted something smog exempt that I could build a sleeper engine for without having to worry about restrictions, but also runs well on the highway as well as off-road.  

Well to be truly smog exempt it need to be about a 67 and most exempt, 68 to 72. 73 saw smog jump a lot with lower CR's and greatly reduced output and 75 saw birth of CAT's. 1973 is pretty much the start of smog engine and greatly reduced performance. I owned a 72 GMC 3/4 ton 4x4 for 10 year that I bought when it was 2 years old. Even stock it was a completely different animal power and MPG wise than 73 and later models. engine output did not really start rising agin to speak of in GM truck until 87 and later when FI became main stream and evolved.