I am a newbie and I am thinking of upgrading the rear control arms on a '72 Chevelle. I was shopping around and ran into these that are made by "UMI Performance"
http://www.umiperformance.com/4000C2.aspx

These seem reasonably priced for what you get.

I would like to know if anyone has experience with UMI Perfomance or reccomends an alternate maker ? Any suggestion on rear suspension upgrades? Adjustable or non-adjustable ? any other variables to look at ?

I am looking to beef up the suspention as a 540 BBC is going in this winter.
Thanks in advance
Jim