I orginally had a th 350 but I blew it up so i switched to the th400 but the question is how long of drive shaft do i need. The th400 is 2 1/2 inches shorter then the 350 so I dont know what I would need and wheres a good store to buy it.
THanks

 

Shorter? A TH400 is one of the longest non OD transmission.

Read this
http://www.chevyhiperformance.com/te...ech/index.html

 

We measured the case of the th 350 and 400 and the cases were 2 1/2 inches shorter. The th 400 only had like a 3 in slip yoke so that could of been the problem.

 

Unless you had a really long tail 350 it shouldn't have been longer than a 400.

Anyhow, you will also need a different yoke, as the Th400 has a larger output shaft. Your best option is to get the proper yoke, put in in the trans(slid out just under 3/4" from bottoming) and measure from the center of where the u-joint cap is to the center of the u-joint cap on the differential.

There is probably a comon length listed in the th400 parts sticky, but there are definitely some variances in the construction on these cars.

 

Well we have the shortest tail on the th400 and we are thinking about going with an external slip, Any ideas on this?

 

Not a good choice. Buy a proper slip yoke and make a solid driveshaft.

 

ditto

 

Definitely stay away from the remote slip joint. Unless you have a 4wd output(won't have a tailhousing) then you should have no issue running a regular slip yoke. Even the bolt-on yoke output shaft will accept a slip yoke.