So I’m in the process of rebuilding the front suspension on my 71 Cutlass Supreme convertible I am also looking at adding a rear sway bar, I have the original front sway bar which I understand is the same as used on the 442, I also have one off a 71 Vista Cruiser, looking at opg they show stock style rear sway bars in either 7/8 or 1 inch, would it be best to go with the smaller 7/8 bar. I am also installing 2 inch drop spindles and stock height umi performance springs.

 

I just installed a 1" UMI rear sway bar in mine and its a world of difference. If you have the stock unboxed rear lower arms, I suggest boxing them or replacing them.

 

I’m looking at the kit to box in my stock control arms, my one concern is I use a 1 inch sway bar on the front can I use 1 inch on the rear or should the rear be the smaller 7/8?

 

I use Summit Racing's own brand bars on my '72 ragtop - 1-5/16" front, 1" rear, along with the UMI tubular rear control arms. Essentially stock suspension/height in all other regards, Koni Street (orange) shocks and Energy Suspension front end links. All rubber bushings in the control arms. Both sway bars bolt right in and no clearance issues.

handles on rails and still easy on the bumps.

 

One rule of thumb is that the stiffer end breaks away first. The A-body cars are understeering pigs, so you want to increase roll stiffness at the rear of the car to make it more neutral. The stock rear bar is 7/8". Bigger is better. Herb Adams used to sell a 1.5" rear bar. You can sometimes find 1.25" rear bars. Increasing the front bar alone just makes understeer worse.