I am changing out the entire running gear on my 65 Chevelle and while at it I am replacing the lowering springs someone put on this car back with original springs and new KYG gas shocks. The front suspension has already been converter to Hotchkiss tublar control arms and disc brakes along with thier sway bars front and rear.
Now I am adding a brand new 12 bolt and while I have the old 10 bolt rear out I am going to change out the original rear upper and lower control arm with new ones I got from Jegs.
My question is how is the best way to remount the rear sway bar to the new lower control arms. I had planned to use the old arms and drill holes in the same locations on the new one as the old ones but since these are tublar control arms and not cheap I do not want to be doing it wrong. If anyone else has done this or knows the best way I am all ears.
thanks in advance for any good replies.

Got my answer from Hotchkissm, if anyone else does this changing from original to tubular rear control arms you mark the new arms just like you did the original making sure the car is level and the weight on the suspension.
Problem resolved.

These "tubular" lowers didn't come with holes for the sway bars?

You probably need to make sure they have internal gussets so they don't collapse when you tighten the bolts (or crack where you drill the holes). They might not be designed for swaybars.

I take it they are Jeg's house brand arm and not Hotchkis (which should come with holes, and your bar is a hotchkis. You might need to call Jegs instead of hotchkis to make sure you don't damage anything since an arm failure would be dangerous.