how do I know if I have the correct "twist" on my torsion bars when installing them? If you put the bar in through the "socket" in the crossmember and then into the lower control arm socket, how do you determine your "hex to hex" location in the 2 sockets? Is it possible to have this incorrect, or will they only fit one possible way?

To check the hex on the bars, do it while they are out. Lay one hex flat and observe the opposite end to see if it is offset 30*.

For installation, yes, it is entirely possible to have the hex offset incorrect between the crossmemeber and control arm.

To check this, you would want to insert the t-bar into the cross member and slide it far enough forward to be on the verge of going in to the control arm. At that point, the control arm assy (lower arm, upper arm, spindle) should be at full droop with no bump stop, and the hex should line up with the bar. If it does not line up, you need to rotate the lower control arm pin until the hex does line up. That is your installation position.

It is posible to have the control arm socket rotated out of position up to 30* as well. This often is the case when you see complaints that the car sat too low or too high after rebuilding a front end and replacing the t-bars.

GEt that lower arm pulled down to line up hex. And that dart is nasty lookin' with those fatties under there.