First question!

Currently running all around, 19x10.5 +12 rims on my Evo X.
Rear guards are flared so i'd like to run a 15mm spacer at the back. Think that should make it flush!

Question is can i run a 15mm spacer at the back fine without upsetting the 4WD system or anything? Should be fine right! Already have ARP extended studs and i'm looking at the H&R Trak+ 15mm Spacer.



Secondly.
I'm running BC Racing BR Coilovers and would like to upgrade to Swift springs.
What specs do i need?!!

Thanks!