700R4/208 to 400/205, driveshaft question

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Allright, I've searched... I've read, I'm still a little in the dark because most previous posts are just about tranny swaps and not tranny/tcase. Installing a TH400 and NP205 (slip yoke) in place of a TH700R4 and NP208; is the slip yoke on the 205 the same spline count as the 208? and do the driveshafts need to be shortened and lengthened?

 

[mountainexplorer]

We are doing this swap right now in an '84 K5. The 700R4/208 came out, and the 400/205 slipyoke is in. The same driveline is splined the same between the 205 and 208. In our case, the 700R4/208 rear driveline is now about 1.5-2" too short and the front 700R4/208 driveline is a couple inches too long. The front 400/205 driveline is a bit too short.

Tomorrow I am taking a longer 3/4 ton truck driveline down to have it cut down to the proper length. You'll probably have to lengthen your rear driveline and shorten your front.

 

[Jagged]

The same driveline is splined the same between the 205 and 208. In our case, the 700R4/208 rear driveline is now about 1.5-2" too short and the front 700R4/208 driveline is a couple inches too long. The front 400/205 driveline is a bit too short.

Thanks! Exactly the information I was looking for. One question for you though, is that blazer still at stock height?

 

[mountainexplorer]

I did forget to add that we also put a 6" suspension lift under the Blazer. But the stock drivelines stayed in with the 700R4 and 208 after the lift and still worked. We didn't have any changes in need of driveline lengthening/shortening until the 400/205 went it.

 

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Thanks for the info