I opted for the Bow-Tie Overdrives 700R4 Conversion
Oops, I see you already bought a 2004R and started the rebuild. I hope all goes well. But, if it doesn't and you decide on a kit:
Back in 2000, when faced with a TH350 that was slipping and sliding under heavy acceleration... I paid in the neighborhood of $1,500 + approx $150 shipping to the nearest transport destination for a Bow-Tie Overdrives 700R4 kit. They forklifted it into the rear of a pickup truck I borrowed to pickup the crated trans...
That was back when Bow-Tie offered only one 700R4; now, I think they offer more than three 'power levels'. I think mine was good for any motor with up to 400-450hp. That's perfect as my engine is probably around 300-320hp and I'm advised my blueprinted Dana 44 with 3.54 Spicers is also good for about 400hp... Kudos to Alan's Gearworks in Clearwater, FL for an exception blueprint and upgrade to what turned out to be a 0-mile service replacement diff (complete with the unmolested rear cover/mounts) I bought with 3.07 gears from e-Bay way back when... for about $425... before Alan's added the 3.54 Spicer gearset and blueprinted).
When I received the crated 700R4 with all necessary parts and instructions, I sat and read the instructions about ten (10) times before I even started to remove my tired TH350. Most stressful part for me was measuring for shortening of my driveshaft that was necessary with the 700R4. I recall you can avoid shortening the driveshaft if you opt for the 2004R. But, by shortening my driveshaft, I also had it re-balanced and new u-joints installed so it was essentially blueprinted as a result also... kudos to Performance Shaft Technology in Clearwater, FL also (you can tell I lived in the Tampa Bay area at the time...).
I found that I still had to have the front driveshaft snout replaced as the trans wanted to leak around my tired OEM piece. That was under $100 for a new one. Also, when I installed the Bow-Tie, I found I had a pesky leak. Kept thinking it was the pan gasket or front seal. I replaced the front seal and pan gaskets... kept leaking. Finally, after removal a second time, I set the trans on my workbench and filled the trans to the 'full' mark and kept an eye on it for leaks... found the selector shaft was leaking... around a seal that was installed crooked! Then, once that was replaced, I found the selector shaft STILL leaked... it was scored/marred so Bow-Tie sent a free selector shaft for my troubles. Once that was all sorted out, I re-installed the unit for the 3rd (and final) time and have enjoyed it ever since. Oh, and I upgraded to their improved Carb plate/mount/cable kit (I can't remember what that cable is called, it controlls line pressure and if incorrectly set, can burn a transmission due to too high or too low line pressure).
Anyway, I hear Bow-Tie really improved the build quality of their kits since my swap around 2000. My 700R4 has been alot of fun and having the off-line performance with the DEEP first gear has surprised alot of people :smash:
So, bottom line, I'd still have opted for the 700R4 even with the need to shorten the driveshaft. From what I've read, there is greater strength in an upgraded 700R4 over an equivalently priced 2004R... the 2004R can be upgraded to withstand equivalent hp/tq but my understanding is the cost is greater (but, I may be behind the times on that point).
My recommendation, read all you can about the strengths of the transmissions and what your performance goals are and buy accordingly.
I performed my swap by myself with my C3 on jackstands in a bay of my 3-car garage. No helpers but it would have gone more smoothly with help in getting the trans muscled up to the engine... don't ask me how I accomplished that... it will cost you a few beers to extract that information! :lol:
Gene I hope you aren’t coming to IL soon I still have a need for that screwdriver. That’s not a specialty tool just a HF dial indicator and base. I took all the measurements but most didn’t come out good so I don’t know. We’ll see going back together. 
