I have no idea who manufactures the parts, but PST gives a 20 year warranty on their suspension parts, and I don't think Energy Suspension does, but I could be wrong. My entire suspension on my 72 Cutlass, and the Celica is PST, and that includes front & rear stabilizer bars as well. They must be made by different companies, now that I think about it, because a few of the guys here had to modify their front bushings to make them work, and those were purchased from Energy. My PST bushings all fit perfectly, with no issues, or modifications needed.