I am afraid of heims on the street. What say you?
The upper arms are not at a 90 degree or zero degree angle to the rear axle. Because of their odd angle, they change angle between the rear end and floor mount as the axle moves up and down. To prevent binding they need a pretty flexible mount.
Ford used a soft rubber at both ends to absorb the angle change. Because they used soft bushing it let the housing rotate, and that causes wheel hop. To control the axle wrap and stop wheel hop, Ford added quad shocks.
The stiffer the bushing you use the less you need the quad shocks, but the more bind you get. This is why dual heims are best for axle control.
Assuming you use the proper bolts, which would have a smooth shoulder all through the bushing center and the frame contact points and be a close clearance fit, you will not get rattles with any bushing. What you will get, especially if you have a hard tire and short stiff sidewall, is a little more road surface vibration or tire imbalance vibration transferring to the body. But any stiffer bushing will do that, the stiffer the worse.
You just have to decide what you want to do more. Drag race with big tires and get rid of the quad shocks by using heim joints or real stiff poly and heim combos, or keep it more stock. Heims will not rattle at all if the bolts are right and heims will not bind, but they feel a little harsh on some road surfaces. They let you get rid of the quad shocks without getting wheel hop.
Whatever you do be SURE the threaded part of the bolts are against the least metal possible and the bolts fit the bushings with minimal clearance. If you don't, it will tear up parts and you will have constant rattle issues. Look at these bolts out of my rear end. I replaced the OEM bolts with shoulder bolts and used thick washers to shim the heads or nylock nuts so I could just snug the bolts without binding. The shim washers set the threads away from the metal so the sharp threads don't push into the metal. You can see what I mean by looking at the factory bolts from my car. (My F250 did the same thing on a rear shock from threads inside a shock bushing. It had the bolt almost cut in half in my truck.)