I have both upper (non-adjustable) and lower control arms. They are excellent quality and can't see any made better. I also installed their grease-able poly bushings in the rearend housing. My car would want to wheel hop with the stock / original pieces in the car. Now with the HR partsnstuff upper and lower control arms there is no wheel hop with my car - 12.30's. My car has the new control arms and MT ET radials 255/60/15's and it hooks perfect.
No down sides at all. Unlike some of the cheaper/more race car type pieces out there.
Buy once and never look back. My car went low 1.4 sixties at the GS nats this year on old DR.
You will be happy you did. Bought adjustable uppers, fixed lowers and there sway bar. WELLLLL worth the $$$ drop my 60' from 1.80's to 1.5X's. Also took care of my rubbing problem with the 275's on the street.