nstalled 99 gmc stock alloys.around 35mph the front end shaking bad scary!

Both 2 wheel drive shortbed trucks. Both 4.3 the 92 5speed the 99 4.3 automatic.

Same tires being used on both sets of wheels? .. Problem is evidently in the wheels or tires!

Same size tires but new. I had wondered if maybe these alloy wheels take special lugnuts to help center the rim on the hub. Ive had a few sets like that but the lugnuts originally on these wheels were tapered acorn which is what im currently using.

Put front wheels on, tighten lugs and spin wheel to see if tire is out of round or tire/wheel wobbles side to side. Wheel should have machined female tapper to match up with male tapper on lug nut... When putting wheel on, it should easily fit flush with rotor hub.