I did the install myself....maybe that prevented any problems....for the rear, I slipped a couple fender washers in to take up the slop....tightened them down and have had no issues since....maybe I would notice something different if I had the ranchos but as it is, mine rides pretty nice....
additionally, I guess I got lucky....it was rusty who answered the phone on a couple different calls....he was very friendly and answered my questions about alignment specs and a few other questions....I got my parts within a couple days and everything was in the box....
I have noticed that my front springs have settled some in the year (plus) that I've had them....I would have asked for the heavy duty springs....it's still good though, just a small loss of height....
also, from the all powerful internet web.....
"Tenneco Automotive is a $3.8 billion manufacturing company with headquarters in Lake Forest, Illinois and approximately 19,200 employees worldwide. Tenneco Automotive is one of the world's largest designers, manufacturers and marketers of emission control and ride control products and systems for the automotive original equipment market and the aftermarket. Tenneco Automotive markets its products principally under the
Monroe®, Walker®, Gillet® and Clevite® Elastomer brand names. Among its products are Sensa-Trac® and
Monroe Reflex® shocks and struts, Rancho® shock absorbers, Walker® Quiet-Flow® mufflers, Dynomax® performance exhaust products, and Clevite® Elastomer noise, vibration and harshness control components."