Rallye Wheel Back Spacing with 3" Trim Ring

I have two Rallye wheels for the front of a Challenger , the wheels are 15X7 and a 3" trim ring will not fit , what is the correct back spacing for a 15X7 Rallye Wheel 4.25? or what back spacing will let the 3" trim ring fit , these were a custom offset so it is not stock , thanks

i believe 4 1/4" to be the back space for a factory 15x7 rallye wheel.

And should clear a 3” trim ring , thanks for the reply

i have only had one pair of those wheels. if i remember correctly, "390" were the last three digits of the part number stamped in the wheel[s].
i didn't have trim rings for these, so i can't say what rings fit.
i'm sure on the back spacing, as they were the same as the 15x7 cop wheels i still have.