I got the 4 inch TC EZ ride lift (springs in the rear) on my '72 and now I am chasing vibrations when I accelerate. I measured the angles and my case is down 6 degrees and my pinion is up 8 degrees. Pretty much as I expected. The pinion needs to be shimmed down 2-3 degrees to get the angles to line up. Before I track down the shims, I am wondering if I am better off lowering the transfer case. It will help out my ujoint operating angles, but I have one concern. I am running HEI in my first gen, and there isn't much clearence at the fire wall. Should I just get the shims and forget the case drop, or should I give it a try?