1972 Blazer 700R4 to SM465 Swap with NP 205

[jfoley]

Hello, I have three questions before I start buying parts and tearing things apart.

1. I have a 1972 blazer with a 700R4 and NP205. I love the OD, but not a huge fan of autos. The other day I overheated the tranny pulling a hill bad enough it started venting. Not sure why it overheated. It was pretty cool out, the blazer has 3:73 gears with 33" tires. Turns about 2500 rpm at 75 mph. Does not have a external tranny cooler. It is a 1986 model and not wired for lock up. It still shifts through all the gears but kind of slides into gear now not hard shifting like it once was. I set the TV cable using a pressure gauge and shift points were correct. I did change the fluid and it was pretty dark. Does this tranny need to be rebuilt? I have rebuilt 700r4s before, but I'm not an expert. I don't want it to fail in the middle of no where and leave me stranded.

2. I have a SM465 complete with pedals, bellhousing, ZBar etc. out of a '71 blazer. To swap this to the NP205, all I need is the adapter for the SM465 to bolt to the transfer case, the 27 spline to 10 spline coupler, and the tall tranny tunnel?

3. I know the 700R4 is longer that the TH350 the blazer came with. Will my drive shafts be the correct length with the SM465? The transfer case shifter is in its original location.

Thank you

[hemi43]

If the fluid was dark, then the friction discs are toast.
3.73 with 33's is not ideal with OD, but will work. IMO, it will be less hassle to rebuild the 700R4 than converting, but that boils down to personal preference.
Maybe now would be a good time to consider a 5.3/4L60E swap. Way more power, more reliable and double the mileage. Again, IMO.