I just picked up a Spohn HD steel driveshaft off a member here, and it seems too short to me. He said he had it in the same set up I do, T56, Moser 12bolt. I installed it and I have close to 2" showing between the end of the yoke and the output shaft seal on the trans, which seems like too much to me, I've heard 1" is ideal. Will that work ok or should I have this ds lengthened 1"? I assume to lengthen it they would have to install a whole new tube and reuse the end caps. Maybe I should just resell this one.

 

Check it with the car at normal ride height. Unbolt the rear u-joint, and slide the yoke into the tranny housing. It should move forward 3/4 to 1" before it bottoms out. Any less, and you could put the slider into the tranny seal on a hard launch. Any more free play than that and you run the risk of twisting the splines.

 

I just got a chance to check it last night and you were exactly right Fred. I checked it with the rear supported and when I disconnected it at the back it went into the tailshaft right between 3/4 - 1". I was releived I dont have to have it lengthened, thanks for your advice.