From SM465 to th400 with NP205

[sandking]

First of all, and I did search, but need some clarification first.

The vehicle: 1972 Blazer with the SBC 350, 4-speed, 4wd, D44 up front and 12 bolt in the rear.

OK, I know I have the SM465 and the NP205 because I researched the casting numbers on them. But I keep reading about things I am not sure of like, figure 8, 32 spline, 10 spline, round, 8 bolts, 6 bolts, etc. These are all Greek to me

I want to swap the 465 for either a th400 or a th350. How can I properly identify the parts I have? I need to know exactly what I need to do to make this happen. What kind of adaptor is needed? The cross member is not an issue, I can make it work. I read that the front and rear drive shafts need to be lengthened and shortened, is this right? I am assuming the th400 is longer then what I have now. Is this process just a matter of pulling the tranny and adaptor, then replacing with the new and having the drivelines done?

Thanks in advance, Joey

[CrashEd]

The 465 has 10 spline output shaft the TH350 has a 27 spline output and the TH 400 has a 32 output.
So to match them the input shaft on a 205 case must be the same spline count.They all 3 take different adapters the 465 and TH 350 use sleeves to connect the input and out put shafts the TH400 has a 32 spline female input shaft on the transfer case. All the older chevy 4x4 stuff is the figure 8 in the early 80s i think it was they went to the round pattern on the adapter on the transfer case side
So here it gets tricky you can change the 465 and TH350 TC input shafts to either the 10 spline or 27 spline but the TH 400 32 spline TC has a bigger bearing for the input shaft you can mill the 10 or 27 spline bearing hole bigger so the 32 spline bearing will fit but can,t go from a TH400 32 spline to a 10 or 27 spline.
The adapter takes up the length difference so the old drive line will work which ever way you go If i remember correctly.
Hope this helps
Ed

[sandking]

It sounds like the th350 is the easier way to go, but is it the right way?.

So is this correct:
I can take a th350 and swap the 27 spline output shaft for a 10 spline output shaft, then use a coupler type sleeve to connect the the th350 with the 205?
Or is there a sleeve that goes from a 27 spline to a 10 spline?
Thanks!!

[sandking]

Oh yeah, what is the difference between a 4wd th350 and a 2wd th350? The reason I ask, is cause I found a deal on a 4wd th350 decently built for $200

[CrashEd]

The input shaft on the 205 case will be the one you have to change from a 10 spline to 27 spline or you can find a TH350 205 case pretty cheap some times don't know of a sleeve that will convert.
The 4x4 trany is the same as a 2wd only with no tail shaft case and a short 4x4 shaft. A 2wd trany has to be completely taken apart to change the main shaft to make it a 4x4 trans.
$200 sound like a buy for a 4x4 trans thats built
Ed

[sandking]

Perfect, thanks!!

Where do I get the sleeve/adaptor?

[CrashEd]

Junk yard or ebay is were i would start. or the best would be to spend $25 and join this board well worth the money so you can put a wanted to buy in the classifieds iv seen several for sell here.
Ed

[72 CustomCamper]

Check out these 2 pages...
http://72.20.96.178/commerce/ccp1133...02-50-5302.htm
http://72.20.96.178/commerce/ccp1134...04-50-5304.htm


Chuck

[sandking]

Originally Posted by 72 CustomCamper

Check out these 2 pages...
http://72.20.96.178/commerce/ccp1133...02-50-5302.htm
http://72.20.96.178/commerce/ccp1134...04-50-5304.htm


Chuck

Thats good stuff, thanks.

[72 CustomCamper]

Anytime...


Chuck