Granny low 4 speed SWAP for TH350 4X4??

[benbloom]

hi truck men, I'm looking to swap my stock granny low 4 speed tranny with a TH350 on my 69 4x4. is this at all feasible? anyone know if it would bolt up without too much fabrication? whats the word on these TH350s are they decent for driving daily?
thanks guys!

[special-K]

It's an easy pretty much bolt-in swap if you have everything you need. I've only done it using a donor vehicle. But, it's easier to go manual to automatic than visa-versa, I had a '71 3spd/Dana20 Blazer, bought a '72 with TH350/NP205 and swapped everything over. Then I decided I wanted an auto in the '71 4spd K/20, so I swapped with the Blazer. Everything bolted in. Never changed any cross members. The only thing I changed was the rear driveshaft on the 3spd to TH350 swap because of the different transfer case.
The TH350 if about as bullet-proof as you can get. Sure the TH400 is even tougher, but most folks never need what extra strength they hold over the TH350, and you don't waste HP using the TH350. Daily driving? Yeah, better when it comes to stop and go traffic. But not sure if that's what you meant. For hiway all transmissions are , then there are overdrive transmissions. I know here in Maryland before the energy crunch, when nothing had overdrive, the speed limit was 70 and now it's 65. So, I have no issues with not having overdrive.

[cleszkie]

I'm actually in the process of swapping out my TH350 for an SM465 in my 4x4 Blazer. The TH350 works fine, but I am after more off road control with the engine braking that a manual trans gives you, and I just plain like driving a manual. As stated above, your swap will be practically a direct bolt in if you get the correct adapter between the TH350 and NP205. GM did us a solid because the TH350 + adapter is the exact same length as the SM465 + adapter. So no cross members need to be moved, and driveshaft lengths don't need to be modified. One other thing to keep in mind - the input shaft of the NP205 will have to be changed because right now with the SM465, it is a 10-spline male shaft. I believe the TH350 output shaft is like a 27-spline male so you need a 27-spline male (or female?) input shaft on the NP205.

[k29349]

Your low range will suck with a Th350 and 205. Th350 mated to a 208 has a nicer low range combo.

[57taskforce]

Id take the bomb proof cast iron case and gear drive of the 205 to the aluminum and chain drive of the 208 regardless of low range. Thats just my opinion.

[swamp rat]

The 205 in my opinion is fine for an occasional dirt road muddy condition, i'm not into wheeling so i'm sure there may be better setups for offroad. I have a 72 with a 350/205 stock, drives great on the freeway and gets me out of a pinch if i get into one.