Why not upgrade to 1LE 10164152 bushings?
Hello,
If you have it apart and are looking for the performance advantage of tubular control arms, why not do the full monty and change the bushings to the stiffer rubber ones from GM? Should give you better feel and stiffness, but not be harsh or potentially noisy like polyurethane ones. This way, whether the stockers are worn out or not, you can upgrade and not be wasting money or time. I paid $130 through dealer for the eight required with 20 percent discount, but an ebay seller has them for about $60.
Also, check what appears to be a crack in the picture on the bushing housing - hopefully it's not, but looks so from pictures. Best of luck.