Wheel fitment help please

[Twinstang]

Ok so I'm getting ready to buy some wheels and it's looking like it might be the billet speciaties line. I'm buying the front G- street subframe from chrisalston Chassisworks and the rear will be there mini tub with there G-link setup.

I want to run a 18x12 rear with a 335/30/18
i was thinking a 5inch backspace with 6 piston calipers so it matches the front setup.



For the front it would be 18x10 with a 275 tire and 5 1/2 backspace and again 6 piston calipers.

Does the backspacing sound right for this setup

thanks for the help ,John