I can not see how you can locate your rear end on a 1965 without a Panhard bar (well you could use a Watts linkage but that would be expensive, and large on a car of this weight). With wide tires and no Panhard bar you would be putting a wheel tire combination through your rear fenders, destroying the quarter panel.
Generally when they talk of factory four link binding it is on a triangulated upper four link with polyurethane plastic bushings that don't flex. In this case the uppers are trying to rotate through two planes of motion. But because the plastic won't deform like rubber it binds. That is not the case on parallel control arms as they only rotate through one axis of motion (like a door hinge). This is why the aftermarket upper arms on plastic bushed replacements for factory four links need a spherical bearing on one end of the upper control arm.
I see no reason to suspect binding as a spherical bearing (Heim joint) can rotate through any angle. This is why they are used (with a Panhard bar) on four wheel drive rock crawlers that have yards of articulation with six foot long four link control arms. If anything where going to bind up and break it would be in this application.
Last edited by Big Dave; 05-08-2018 at 04:31 PM.