Ok my 4L60E is 30 3/4 inches long
My new 4L80E is 31 1/2 inches long

Both are short slip yokes

Art Carr says the 3/4 inch difference wouldnt matter and I could PROBABLY go ahead and just have a TH400 yoke put on my current driveshaft without shortening it. I have a custom length Spohn Performance steel driveshaft that was made for my 4L60E and 12 bolt.

Does anyone have an opinion here? Should I pay the extra $100 and CUT my brand new driveshaft 3/4 of an inch ? or just put a TH400 yoke on it and keep it the current length?

 

Well to be honest I dont have an answer, but I would like additional information on the 4L80E swap and why you went that direction. Either in a PM or here.

I guess I'd do the Yoke.

-Dustin-

 

To be honest... I think you should measure the lengths and take the measurements to a driveshaft place and let them decide... if a place that does it for a living and will stand behind their product as-is then go for it...

I get all my DS needs taken car of at Denny's, he's done this for a long time and knows what works and what doesn't, and he stands behind his products...

 

well 3/4 of an inch doesnt sound like much but if it bottoms out in the tailshaft it will take the seal with it.

Everything is the same except the 4L80E would have an extra 3/4 worth of the yoke in the tailshaft and Im concerned this may be too much.