Has anyone done a swap from a 4 speed manual to a 700r4 behind a 6.2? The reason I am contemplating this is that my 4 spd has a bit of a growl that gets louder as the tranny gets hotter and I just happen to have a nice 700r4 sitting on the floor of my garage. Any ideas on what all would be involved? Oh, and it is a later model 700r4 from a 4x4 with the electronic control plug (the square one with 4 prongs I think). Thanks in advance!

Is your truck a 4x4? If it is it would require replacing the input gear on the transfer case to a 27 spline input. Personally, I wouldn't do the swap. 700's are good light duty transmissions but don't live very long with heavy trucks or towing. You would need to replace the governor and do some valvebody work if you decide to use it however. I would just rebuild the 4 speed.

Well, that is not really what I wanted to hear. I had planned on doing some light mods to the r4 anyway and was looking forward to having an OD. With 410 gears, she is singing pretty good by 50mph! I wonder if a newer 5 spd would fit? Oh, and yes it is a 4x4. I'll see if I can post a pic of the old girl. I've done alot of work to her over the last year.

Here she is.

Nice looking truck! A lot of the early chevy's came with 700r4's even in the 3/4 tons and I owned several of them and replaced several of them, but overall they are a pretty good tranny. My daughter has one in an 86 Blazer with 3/4 ton running gear that I just rebuilt two weeks ago and I like it for her application. If you decide on the swap, you will need some sort of valve body modification, (I just bought a 4th gear lockup kit for the 700r4 in my cj7, it consists of a pressure switch and plug kit to replace the 4 pin plug, one wire hook up). The governor will need to be replaced with a diesel unit. Torque converter seems to be weak link behind a diesel. You will also need the TV linkage and brackets. The overdrive is a nice feature, but if you really want an auto, a turbo 400 will bolt right in and mate up to your transfer case. The 700 requires changing the input gear in the transfer case. The last swap I did like this was backwards to what you want, my dad had an 83 6.2 powered suburban and we pulled the 700r4 and put in a 4 speed and a US Gear overdrive, goes between trans and transfercase. His rig had a lot more power with the manual than with the auto. I still say rebuild your 4 speed, probably just a bad bearing making your noises. Then maybe up your tire size to 35 inches and you will have the equiv. of 3.73. I ran this set up for quite a while on one of my projects before I came across an nvg 4500. The nvg 4500 will go in without much trouble also.:rolleyes:

Check with a trans. shop that does manuals and see what it would cost to replace the bearings. If you do then I would replace the forks at the same time.

Split the case and replace the shift fork silencers (nylon liners) in the transfer case while you have it out. If it hasn't already spit them out into the bottom of the case, it soon will! Easy fix, cheap insurance! Check the magnet for metal/debris and repair accordingly.

Thanks guy's. I guess I am going to have to give this some more thought.