Here is some starting info from a swapper who has had to redo a few things because of bad advise from some
Dirty dingo mounts will allow you to keep your drivetrain in place but you will most likely have to move the ac bracket and often times you have to notch the front cross member an unsettlingly large amount - There is a company on that facebook page called Tejas Steelworks, they allow for your ac compressor to stay in place but you have to lengthen the rear drive shaft and shorten the front one most likely but that will also depend on what trans you have and what you want to use. I say use his and get a custom rear aluminum driveshaft made anyways when it comes time because the LS motor puts out more than the stock smog 305 or 350 by a long shot and when you start adding up the forces involved and the torque your driveshaft will probably crap the bed. We've been seeing a rash of it happen with the C10 trucks lately. With the Tejas mounts you should be able to use all the Stock LS parts, including exhaust manfifolds, and down pipes for housing the front O2 sensors. You can do a CAI for your MAF sensor and also if you relo the battery you can do the stock airbox. More fo the stock truck parts you can retain means less money spent on your swap. That fellow also sells some good PCM/fuse block mounts and a fan shroud if you want to convert to electric fans (all the cool kids are doing it, and I probably will as well once I get my stuff sorted). The guys name is Scotty, and he has done a number of builds and really gives good advice overall.
Cooling details-
You can use a Spectre cu730 radiator off ebay, amazon, advance auto and it has lines to insert the steam port... Or you can use an old school big block radiator and put your steam line into a cut in adapter that has an inlet for it... (many ways to skin that cat)...
Wiring you can DIY if you are able to read diagrams and are attention detailed. I think the site that can help the DIY portion of that is LS1Tech.com (don't quote me for certain there) If not you can get it done for you for around 300 to 500 bucks and that will usually getting the anti-theft stuff removed out of your PCM and a base tune. I would recomend LSX Specialties because they seem to do quick fast work, and their return product looks exceptional.
Plan on replacing your gas tank to a tbi unit, and getting that matching sending unit with a fuel pump from any era Vortec or LS truck. Also plan on replacing your fuel lines, there are two types of systems, return and returnless.. That'll depend on what motor and setup you get. The TBI tanks have a baffle in them to keep the fuel pump submerged and cool. Some will say run an external pump, but I've seen too many of them fail, and they are annoyingly loud.
Go ahead and plan on getting a transmission and motor, harness, PCM, and all the accessories as one. If you have a 700R4 and plan on keeping it, I really would plan in using the 4l60E. Chances are you will smoke the 700r4. Plan on getting a 4l60E or better yet a 4l80E. if you insist on sticking with your 700R4 then you can go to bowtieoverdrives.com and get a TV cable adapter but its about 180 bucks and that will only work with a drive by cable throttle body. Regardless of your trans choice you will need an adapter for the transmission to your transfer case. Look into advanced adapters. If you had a TH400 then you will need to replace the input shaft on the NP 208 with a 27 spline, vice versa if you had a th350 or 700r4 and are getting a 4l80e. Plan on rebuilding the transfer case to correct that and replace worn parts.. It's just good preventative measure for having to drop it all twice (or more considering your trans choices). On mine the 4l60E was the same length as the 700r4 and I was able to find a 1997 model that had the 4 bolt rear housing so it went straight on to my transfer case adapter, and the driveshafts matched up, along with the shifter linkage, and not having to monkey around with redrilling the trans cross member holes. The catch 22 is if I have to have that trans rebuilt it will probably cost more than a more modern 4l60E, and if I swap it to a rebuilder then I'll have to get a new adapter because of the change in the tailhousing (6 bolts on the newer ones vs 4 on the older ones).
Plan on getting some kind of VSS adapter for your transfer case to provide the PCM a speed signal at the very least. ON mine I have gone with a dakota digital unit that provides an 8k signal to the PCM and then I got a dash unit and reconfigured the wiring out of a 1991 4wd Suburban. It allows you to calibrate the speed with the PCM and has no speed cable. Ultimate in adjustability for tire and gear changes... Some will say you don't need it but when the 4 x4 component comes into play when things don't get the right signals the trans stops shifting out of first and either weird idle problems can pop up.
Those are some rough basics. There's a ton of info on that facebook, after all its for LS swapped square body vehicles. There are lots of generous people that will offer advice (both good and bad) so I would basically figure out what you want out of your truck and make sure when you get advice it is oriented around a 4 x 4 setup, because most guys will mouth off and give 2wd advice that will end up wasting money on parts that won't quite fit (sucks but it happened to me some).
If you want daily driver dependability you can do that and even get your cruise control working (if you have it) and easy to do that part it if you don't have it to be honest.
There are guys who will tell you a swap can be done for 500 dollars. I'd say a more realistic price is around 2K but that will also depend on your ability to DIY, improvise, and what all tools you have to buy (versus what you already own)...
Please feel free to shoot me a PM if you have any questions and I'll do my best to offer the straight shoot. Some things I do not know right off the top of my head because my 1984 Jimmy is at a phase where I could have it running but nothing is painted and its all dirty because I have been doing the swap out of a single apartment garage. I'm about 2 months from my house being finished so I decided to hold off on getting it running and full of fluids, simply so I can break it down, clean it (and anoint my driveway with sanctified GM fluids), and paint all the stuff up nice and neat so I have a good clean starting point. I also want to do up the cab mounts and throw in a 14 bolt in the rear, plus paint that axle and the front axle when I do a 8 lug conversion, so as you can see I figured it was best to leave it undone so I can really make it like new.
