You don't need BB's or Equal, you just need someone who knows how to balance tires and will take the time to break the bead a few times and spin the tire on the wheel until its in the sweet spot. That Equal stuff is for Semi's or Tractors not passenger tires.

 

My 15" aluminum wheels actually have more clearance between the caliper and rim than my steel Cragars did. Here's a thread I started on 15" wheels.

FWIW, 3.25" backspacing is probably going to give you more clearance than 3.75" is. They will stick outside the wheelwells farther. I have 15x8 with 3.5" backspacing, check out the thread I started.

https://www.jk-forum.com/forums/jk-show-tell-33/official-show-me-your-jk-15-inch-wheels-thread-7758/
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I have a set of Bias Ply TSLs that you can go and try to balance to your hearts content and after you add some ungodly amount of wheel weights and you think it is all good I will take it out wheeling on ONE trip and rip every single one of them off on the rocks