You are modded so I would stay with a 305/45R18 ET STREET R on a RTS 18X10 rim. It is 1" taller and will have a longer contact patch.I am thinking about putting some either 18 or 17 inch Weld or HPP drag rims all the way around and running MT ET Street R's on the rear. I am planning on getting the shortened sway bar connectors for the rear. My questions are this. 18 or 17, any preference and why? Also, is there anyone running Welds Weld RTS S71B all the way around because I am concerned that they will not work for the front unless I go with skinny's. Has anyone ran skinny's on the car? If so, what differences or concerns did you experience. Thank you.
You need a 1/8" spacer with a high pad to run the weld rims on front. Lots of Guys are doing it and to confirm you can call weld.
For the front you can run a 20X7.5 with 3.8 or 4.3 backspace. If you do not want to sink the tires inward I would run the 3.8 PN 71HB0075W38A 4.3 71HB0075W43A I would be sure what tire you want to run before ordering.
For the back I would run a 18X10, 6.6 backspace (+28mm) 71HB8100W66A