Big tire guys help

[casperfast]

Looking for input from guys that run large tires. I have about 4-6 mm clearance between my tires and the upper control arm in the rear with tires at 30 psi. I jnow when I air down it will rub. Im trying to figure out what size spacers I need. I was thinking 10-15 mm. The wheels are a 40mm offset. I already have extended studs ready to install. Thanks.

 

[casperfast]

well after lots of measuring and reading i ended up getting 12mm hubcentric spacers off amazon by "uber technic". the apcers were dead on and had the 67.1 mm lip the perfectly fit my wheels and hubs. i spent yesterday installing my arp extended wheels studs and mounting them all. i did some test pulls on my car. since i at the same time installed a new tial wg with 23.5 psi spring set i was overboosting with the current link controlled boost controller. i disabled it after i pegged 39.6psi. this resulted in the wg pressure line blowing off. ( didnt know at the time) so i disabled the ebc in link thinking i would have spring pressure but was again hitting 40 psi. so i stopped doing pulls. but i did do one launch on launch control but i only allowed to build about 6 psi, it smoked the tires until i let off. im hopping that was just from the hoosiers being brand new.