Gears & Axles - Did an LQ9 swap... Now I got a vibration at speed...

I swapped from an LS1 to an LQ9; just completed the swap today. The only things that are new and not just swapped over are a fast intake and a monster stage two clutch. After doing a few searches I'm starting to think that it's my U clamps ... Maybe I didn't tighten them correctly; anyone know the correct procedure. The vibration only occurs at speed and occurs regardless if the car is in gear or not. Any other ideas??

Nobody has any other ideas?
Anyone know the exact procedure to tighten U bolts?
A torque spec would rock?

First you need to check the U-bolts that hold the U-joint in the rear yoke. Did you do that?

Al 95 Z28

I'm going to do that as soon as I get home from work.
I went down to the parts store and picked up a brand new U joint. I figure if I don't need to replace it then I can return it tomorrow.
Reading online though it looks like I need a press to replace the U Joint.. :(
I'm not sure if I know anyone who has one.
I'm hoping I just over tightened the U joint and re-torqueing them will fix the issue.

Alright.. so I found the issue. It was the U joints.. but it wasn't over tightening.
It was actually under tightening. I guess in my haste to get everything done I put the drive shaft on and tightened the bolts in until there was resistance and then decided to "torque it to spec later" ( this is something I do a lot and never forget.. until now ). I have to say I'm extremely lucky it didn't let go...
Anyone know the torque specs on the U joints? You could probably could have fit a penny between the clamp and joint itself...
I tightened it up with a wrench but couldn't get a torque wrench under there... my driveway is at a considerable incline and I can't jack up the car so I'm going to take it into a shop down the street to torque up.

my driveway is at a considerable incline and I can't jack up the car so I'm going to take it into a shop down the street to torque up.

Just make sure they are seated all the way. Be sure to look at it close.

Al 95 Z28