700r4 spacer

[6T8]

I got into some old posts on installing a spacer when changing a th350 over to a 700r4 with np205. The one listed as #7q35A from A&Reds Transmission parts, you needed to cut 1/8 in off output shaft. That # is outdated in their catalog. Was wondering if anybody else has come up with a spacer that you don't have to cut shaft? A&Reds spacer is only $60. AA is alot more.....Rick

[amcgeh01]

Originally Posted by 6T8

I got into some old posts on installing a spacer when changing a th350 over to a 700r4 with np205. The one listed as #7q35A from A&Reds Transmission parts, you needed to cut 1/8 in off output shaft. That # is outdated in their catalog. Was wondering if anybody else has come up with a spacer that you don't have to cut shaft? A&Reds spacer is only $60. AA is alot more.....Rick

Hi Rick,
Yes, I ran into the same problem on my conversion.. 5.3/4L65E/NP208 into a 1972 GMC Jimmy 4x4... I had no choice but to order the kit# 50-0405E which was $270+... Luckily I still had the original 700R4 and the Tcase still connected so I could use the mating plate along with AA's plate to make everything work.. My other option was to look for a very scarce NP241 with VSS that has the pass side drop.. AA's plate slides between the trans & Tcase and you input the VSS connection and Wah-la you get the 40 pulse signal and the ECM is happy... At least in theory.. LOL.. I will install it in a few weeks after it gets here.. - A.J.

[west9378]

I just purchased a shaft from Bowtie overdrives but when it arrived I found it came from Advanced Adapters it is a short shaft that will make your 700r4 just like the 350 and able to bolt up with no spacer.
http://advanceadapters.com/product/1775/50-6900.html
hope this is helpful.

[SeventyOne]

Originally Posted by west9378

I just purchased a shaft from Bowtie overdrives but when it arrived I found it came from Advanced Adapters it is a short shaft that will make your 700r4 just like the 350 and able to bolt up with no spacer.
http://advanceadapters.com/product/1775/50-6900.html
hope this is helpful.

Just received my order from AA - It's a nice looking piece. Others on this board have used it as well but I haven't had the chance to install it yet.

Be aware that the 700r4 is longer than the Th350 and you will have to move your engine forward or tcase back to accomodate the extra length. As you can guess this will also complicate things like radiator hoses, throttle linkages, TV cable, drivelines, and exhaust.

[SMORT]

Doing the same w my '70. How big of a deal is it to put the short shaft in the trans? Should I take it to a trans. shop?

[Thealien]

Originally Posted by SMORT

Doing the same w my '70. How big of a deal is it to put the short shaft in the trans? Should I take it to a trans. shop?

The output shaft is about the first thing that goes in the transmission so its basically a rebuild. May as well have them install a beast sunshell as the stock sunshells are prone to breakage. Check all the clutches while in there and replace if needed. Thats what I did when I had that shaft installed in my 4L60. A local transmission shop installed the shaft, clutches, and sunshell for about $300 not including the cost of the shaft.

[west9378]

I am in the process of rebuilding my transmission so the process to install the short shaft was no problem.

[sierra4x4]

I have heard that it is better to run the spacer instead of the shorter tailshaft becouse with the short shaft you run int clearance issues with the cv on the front driveshaft and the side of the trans pan.

[Thealien]

The 700R4 is already about 2 inches longer than the TH350 so you either have to move the engine forward (there is little clearance between the crossmember and front differential originally) or move the transfer case back which would mean shortening one driveshaft and lengthening the other and having to deal with moving the shifter. Adding in another spacer only adds to this (there is a member who said he did this with no major problems).

Here is a picture with a 700R4 with the engine moved forward and a 2-3" lift. The driveshaft is very close. I will be dealing with this soon on a 4L60 with an AA output shaft and adapter which makes it the same length as a 700R4.

[6T8]

Thanks for all the info..........Rick