1999 ford ranger 4x4 shaking?

I have a shaking in my ranger. Feels like a bent rim. Starts out with very little wobble from taking off. Then between 40-50 mph its very bad shaking. I have replaced tires. Rims. Front bearings. Replaced the air lock hubs to Manuel hubs. Replaced rear end gears and bearings. And back hubs. Replaced all the brakes. And it still does it. Before I changed my tires the shake was barely their. And then I changed tires and it was bad. Iv tried different rims and bought brand new tires. Which have been balanced. I'm at a loss. Iv also replaced ball joints and tie rod ends with all moog parts. Also changed rotors.

Jack the whole truck up, have someone else start it, put it in 4wd, put it in gear and get to 50mph, and you check the rims and anything that might be shaking. Could it be an out of balance drive shaft?
OR
Have someone else drive the truck on a highway or expressway, while another drives you near by so you can inspect both sides at actual highway speeds.

Check control arm bushings and (perhaps--IDK) if it has strut bars running from control arm to frame--check those. Pitman arm and linkages would be next. I'm surprised you've yet to set the ranger wheels up in the air and check for slack in steering.

Check the engine mounts.