From adding 4.10s? No. But, if racing on slicks, then yes, full length subframe connectors are recommended along with welded axle tubes and torque boxes.
:rlaugh:
I just finished reading/looking at the 13 page Thread. I need to go buy 2 bottles of this stuff. I want to see how bad it will smoke with 28,500 miles of abuse, should make for a good smoke show. :D