bolt in sub frame connectors

I've got 64 Barracudas with and without subframe connectors. There is a night and day difference. It is noticable from the time you open and close a door. The ride and handling is so improved with them. Rattles and squeaks are minimal. The car without will get them in the near future. My car has the US Cartools weld in and we put a set made with rectangular tubing (weld in)in a friends car. I doubt anyone could tell the difference without looking underneath the car. I have not used bolt in connectors but I would want to weld them after they were located.