So I have the SPC front upper and lower arms, tall ball joints. Unfortunately SPC doesn't make anything for the rears. Anyone have suggestions on what to use? Tim
Depending on the $$$ BMR, QA1 stuff works well. You can always crosscheck "Chevelles" if you dont find much info on Buicks
If You drive it on the street often,i would go with something like roto-joints from Sphon, Ridetech or SPC. I tried polyurerhane but it's catastrophic. Rotos mixed with QA1 unibaals works queit and is super comfortable on my Riviera.
She is driven everywhere. I have checked with SPC. Which is were my front set up is from. They don't have anything for the rears.
I did the UMI Performance # 401417-B , They do Roto-Joints also just more expensive, shop around soon for the Black Friday deals, Usually UMI & Summit will have them....
I had boxed LCAs with polys on both ends end poly in both ends of panhard. Ride became harsh and unpredictable. I don't know, maybe on super smooth road or track poly bushings are good but i doubt it. With poly, there is no place for free articulation, there is only one big permanent bind. Maybe upper front a-arms but there delrin is a master. After i installed uni balls,boom like a charm. This and a set of Bilsteins b6s made night and day difference. Anyway, everybody has to decide for them selfs, i already took that pricey lesson. You can take it or leave it. Just my opinion and observation. Peace, Kacper.
Interesting - I asked b/c I had urethane (front/rear, upper/lower on my '70 GS so no panhard) and really liked it.
I was happy w/them on my last GS (upper/lower, front/rear + front bar) but it also had a rear anti-swaybar/boxed lowers & a TA front bar & KYBs. Lightweight too (low option 350 4-sp) & handled incredibly well. Surprisingly, none of the 3 GS's I have now came factory w/F-41. Will likely add it to the convertible. Not sure on the other 2 as they're likely getting more authentically restored but we'll see.
I found that the factory rear bushings are incredibly "squishy" so to speak. With the rear axle out, but the control arms still mounted to the frame, you can swing the lowers quite a bit left to right, with urethane bushings not so much, so thats telling me yes, theres still some compression/deformation but its not the marshmellow feel of stock rubber bushings.