Back up a bit.
You moved the tires, so it’s clearly not the wheels and tires.
Vibration on acceleration is axles. During cruise it can be many things, but you are feeling it under the floors under acceleration so, axles.
“my guy doesn’t use junk” isn’t an argument. It isn’t even true.
Rebuilt axles from big box stores are junk unless they’re new. Even if he got them at NAPA, they’re rebuilt junk.
If you paid less than $500 per axle, the price of a new, not rebuilt, axle, then yeah, you got junk.
Believe me, or live with the vibration. Your call.
You may have multiple things wrong with this car. Find, and fix if needed, all the other things I mentioned in the previous post. But it is going to come back to axles.