After recent wrenchin I have a vibration during braking. The faster
and harder the braking the more severe it is. Under light braking I have no
vibration. It is not like warped rotor pulsing, it is more side to side or general vibration or shaking.

Recent wrenching:

1. Services rear brakes, new chevy master cylinders, shoes. I had a hell of time getting the drums off and used a BFH. I have put the truck in reverse and hit the brakes and seems to stop excellent, no noise, no vibration. I have not gotton up to any considerable speed in reverse and done this though. My concerns here are I damaged the drum of of round or incorrect shoe installation.

2. I broke the drivers side caliper bleeder screw and just exchanged for a new caliper.
!!!The old caliber had a very tight fit on the rotor and did not float by any means. so....when I took the caliper off and put the new one on which floated (side to side) I noticed that I could now move the rotor assembly...unit bearing. So the variables here are the unit bearing, rotor, and my new caliper.

The truck did not do this before all of this work.

Any opinions is appreciated to save me time and money.

 

To check rear drums. Drive approx 30 mph and apply parking brake and see if have vib. Note: hold the release lever out while doing this.
You said bearing loose in front.
side to side shake at 30 mph or so might be failed belt in tire, Loose wheel bearings, warped rotors, suspension wear.
Have fun.

 

I would replace the other caliper with an identical caliper. I think it is better to do brakes in pairs as not doing so has caused ghostly problems, and near disasters in the past.
I say identical because a buddy was having probs with a caliper replacement and it turned out the reman co. boxed two similar looking but different piston diameter calipers in one kit and made the car pull. It was pretty hard to diagnose and was finally solved by just starting the rebuild over from front to back.