Th350. . .2wd/4wd???

atomicjoe23

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I was looking on Advance Adapters website for an adapter for a TH350 to an NP205 and they have 3 choices of TH350 trannys. . .2WD, 4WD, and 2WD/4WD. . .I had no idea there were different versions of this transmission. Are there different versions of this transmission? and if so, how do I tell which one I have?

Thanks!
 

scottm

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The 350/205 combo came stock in blazers and 1/2 ton burbs up to 74 or 75. I used to have the part number for the factory adapter piece. 4wd trannys dont have a tailshaft housing, just a splined shaft sticking out of a mating surface with a bolt pattern around it. You need to watch the transmission shaft spline count. 205's mated to the Muncie 465 manual trans and th400 apps had a heavier spline, but they used a finer spline with the th350. I would search Pirate 4x4 for all the info in the world on this stuff.

You can make any th350 work by getting the right trans output shaft for your t-case from advanced, and building it into your trans. Then get the adapter from advanced or search ebay and pirate for a factory adapter. Another idea is to search craigslist for 73-75 blazers and burbs being parted. I bet you could have a factory 350/205 combo within a couple weeks.
 

atomicjoe23

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I got an NP205 and a 5-spd manual out of a '73 Chevy P/U the same day I picked up the 14-bolt rear and D60 front axle we're gonna use for our '49 Jeep Willy's P/U truck project. . .bet they would mount right up to the 350 SBC and I wouldn't even need an adapter!
 

scottm

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No, the spline on the manual 205 will be different than the th350. Again you can get an output shaft with the right spline from advanced and build up the transmission for it. Or you could get a th400 and it should mate right up with a 400/205 adapter. Also the manual trans you have should be a muncie sm465, which is a 4 speed.
 

atomicjoe23

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I haven't verified the manual transmission yet. . .because the NP205 and the manual were just freebies the guys asked if we wanted while we grabbing parts. . .everything came out of a '73 Chevy pick-up.

The TH350 I have right now has a Dana 18 twin stick attached to it. . .this is what came with the '49 Jeep Willy's truck that is our current project. In talking with Advance Adapters they suggested ditching the Dana 18 and going with an NP205 or an Atlas, and since I already have an NP205 that is what I want to go with.

If anyone knows the part number for the factory adapter for the TH350 to NP205 please post it up. . .I'll do a search on Pirate4x4 as well.

Thanks for the info ScottM!
 

johnnyweb

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Damn just sold my old 205 w/adaptor plate that cam of my t350 out of my blazer a couple of months ago. They are out there. A Suburban is what i had gotten it out of years ago. The 205 t case is strong as hell but it has a higher low range then alot of other cases. They make a kit to convert it to like 2.8 to1 or something still a little high geared for my taste.
 

atomicjoe23

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I just double checked it. . .it's definitely an NP205 and the serial plate says it has a 1.96:1 reduction ratio. Yeah, the NP205's are supposed to be really strong, plus it's gear driven instead of chain so I don't have to worry about chain stretch and Advance Adapters now makes a twin stick for it. . .so you no longer have to bastardize a Dana 300 t-case twin stick set-up to have a twin stick NP205. . .something I'm thinking about.

I double checked the transmission that came with it and it's an SM465 4-spd with a 10-spline output shaft.
 

jpndave

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Try checking with Novak. I was in there last week and I think they have some good used adapters for the 205/350. I'll try and remember to check when I stop in there next week. They are here www.novak-adapt.com the 205 cases are brutal strong (heavy though).
 

atomicjoe23

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If someone describes a TH350 as a "short shaft" does that mean it's the 4WD version?

Thanks!
 
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