I recently got around to installing my wheel since i just got the car running, they are staggered C4 ZR1's (17x11--17x9.5).
i cut the bump stop and they dont rub on the inside but if it bottoms out hard enough it will hit the the outside lip of the fender well.

So my question is i need to bring them in maybe 1/4"--3/8" on each side how much can i safely have the back pad machined? Can i get away with the 3/8" i have a 4th gen rear end and no spacers so the only way to move them in is to machine the back pad does anyone have any experience with this??

 

You can roll the fender lips in so that will gain you some room & reduce the amount of hub you'd hafta shave. I assume that you mean the hub of the wheel?

 

I rolled the fenders already but its just a bit off I'm just wondering if I can safely shave off enough to tuck them I asked the machinist but be said they couldnt be shaved down but from what I heard there is an acceptable amount that can be shaved off
Here are some pics of some test fitting I did with the rear springs removed

 

No shop with tell you that they can shave a wheel due to possible liability if the wheel fails. I've been down this route before with wheel manufacturers & machine. And I wanted to shave the same 1/4" to 3/8" max.

If you can talk them into doing it, you'll likely to either be asked to sign a waiver and/or the receipt will state that it was not recommended & that the company assumes no liability in any case of failure.

 

Its generally a bad idea to machine the pad on the wheel, if you look in the lug seats, you can see how thick the lug openinng is after the taper and its generally not thick enough to be able to remove much material. I would advise against doing it

 

ill have to measure the thickness i may just end up leaving it alone if its not alot of material in there

 

You may just have to get mini-tubs.

 

Fender flares??

 

No this will be driven a lot I'm not gonna get drastic with it it'll be fine the way it is I guess its more of a personal preference to have them tuck at its present ride height rubbin issues will be minimal I'm hoping lol ill do some measurement see how much material I'm working with I figured someone had done this already
If I have them shaved ill post pics of final fitment

 

Roll 'em flat or even do a slight pull. You can work those fenders a lot more. The lips still roll inwards.

 

After I rolled the lips and lowered it more I took it out for a spin and no rubbing anywhere I still need an adjustable panhard bar to center everything but besides that its all too good go!