What size tubing (dia. and wall) is used to put poly bushings through for say a motor mount or like in the front hoop thread the mount on the frame. And what bushings are used (application if possible)? I am going to start fabbing motor mounts and some other stuffs and am looking at costs.

I used the smaller Jeep YJ bushings most of the time. These use a 1.25 ID, so depending on the application, I use either 1.75, .250 wall or 1.5, .125 (or even .120) wall tubing. You can get two different inserts for these bushings: 1/2" bolt or 9/16". Does that help?

Also, you can buy these things already put together at M.O.R.E. (Many different sizes)

Thanks it does help :D What about for bigger bolts??? I want like 5/8 or 3/4 for the motor mount bolts I mean all the torque from an SBC on a 9/16 is asking for hell to raise through my oil pan...