I'm in the process of installing tubular control arms on my 71 cutlass. You're suppose to torque the bolts on the control arms with the car down on it's tires. My question is will there be a difference since I haven't installed a motor in my car yet or should I wait till the motor is in then torque the bolts. Thanks

 

Wait. The suspension needs to be loaded at normal ride height.

 

So you're saying put everything together and wait till motor is in and then torque everything down. I'm going with coil overs so I will need to set ride height on those then torque everything down.

 

Yes torque all rotating suspension points at loaded ride height.

 

What type of bushings?

Rubber: Yes, definitely. Just wait.

Polyurethane/Delrin/other plastic: Go ahead and torque now.

The mounting ears squeeze down on the inner sleeve and stop it from rotating. The outer sleeve is always narrower, and the bushings themselves always have some give. In rubber bushings, the inner sleeve is bonded to the rubber which is bonded to the outer sleeve, so they rubber stops the sleeves from rotating. That's why if you torque them when drooped, then the rubber is constantly twisted and will tear much sooner.
On poly/plastic bushings the inner sleeve can rotate separately from the bushing, and the bushing can rotate separately from the outer sleeve, so this isn't a problem.

 

Good point on rubber vs poly. I just figured with his statement "You're suppose to torque the bolts on the control arms with the car down on it's tires" that the instructions on his parts said to do that.

 

The manufacturers include the same instructions with poly/delrin parts also. "Just Because". It's easier to say the same thing than to spell out the details - like the 14" wheel and disc brake thing.