Mating a 4L60 to an NP205 (part of my 5.3 swap)

[1972K20]

Crash,

Did you use a 2WD 4L60 in your build?

[Crash_OK]

Originally Posted by 1972K20

Crash,

Did you use a 2WD 4L60 in your build?

Yes I did.. I decided to answer you PM here..

No, you will still need to replace the tailshaft. Doesn't matter if it is a 2wd or 4wd 4L60e. Below are some of the steps required to do this conversion using the advanced adapter kit.

•Replace the tailshaft (requires a teardown of the 4L60e) AA Product# 50-6900 (http://www.advanceadapters.com/produ...placing-th350/)
•Mount the transmission to Transfer case adapter and VSS pulse wheel. AA Product# 50-0405E (http://www.advanceadapters.com/produ...onadapter-kit/)
•Modify the coupler that connects the transmission to the NP205 by cutting it down by 1/2 inch.
•You will need to have the stock adapter that goes between the transmission and transfer case machined down some. http://i284.photobucket.com/albums/l...asetotrans.jpg

See page 4 of my build for more of the process. http://67-72chevytrucks.com/vboard/s...=494599&page=4
After all of this is done you will need to either move the engine forward 1.875” or move the transfer case/transmission cross member back 1.875” (This will require some driveshaft modifications).

I have heard that there may be an adapter that allows you to use a 4wd 4L60e without replacing the tailshaft. It adds an additional 3-5” to the length of the transmission to allow this. I do not know much about it, but I bet you could find it with a Google search.

Hope this helps

[1972K20]

Cool! Thank you!
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[The Blue Pig]

Wow. I have been sitting here trying to absorb all of this for a little bit now. I have a 72 K20. I just bought a 99 suburban with a 350 vortec and a 4L60E. I want to order the adapters but I'm getting slightly confused. Crash says to get both the 50-6900 tailshaft and the 50-0405E adapter. When you go to Advance's webpage on the 50-0405E, it says that if you're using an AA tailshaft, then you need to use the 50-0405 instead of the "E".

uhhhhhh.....

In the end, what worked best? I also sent Crash a pm concerning his use of the factory T-Case mount vs. the aluminum one that it looks like Thealien used. What were the pros/cons of each, what would you do if you were to do it over again?

Thanks guys!

[1971k567cam]

I am in middle of same swap. I already had shortened shaft from my 700r4 so bought 50-0405E adapter kit. I was wondering if anyone has pictures of modified stock adapter and how to do it? Do you remove brg and install sleeve in its place? The info from AA is very not helpful at all