Are my tires to big?

I have 275/40/17's all away around on my 96.. I think the tires are rubbing. Especially when someone rides in the back. The other day, myself and my wife rode up front and my mom rode in back of the car. I live on a twisty curvey road... I kept hearing this weird noise, so i stopped and check.. lole and behold.. my passenger rear tire has a few small chunks out of it.. it could also be my shocks, right? I think those the stock ones.. whoever owned my car did not have the same passion for it as I do.. therefore maintenance was not done on anything other than oil... At least I hope.

If it is tires, I wanted 555s.. but I really never race, I mainly do the twisties more than anything.. so is there a good handling and gripping tire? What would the correct tire size be? Also, when I get back home, ill check my suspension and may be able to talk my wife into this sweet 1500 dollar kit, comes with all kinds of nice suspension goodies. Thanks for any input. Also, just to clarify, my mom is about 150 pounds.. so no bigness in the back.
 
Other than the contact, does the car handle as you would like? The shocks only dampen the bounce, the springs hold the weight. You could go to a higher spring rate in the rear but this would stiffen up the rear of the car and change it's road manners. What year is it? How low is the car? Rolling the lip in the rear quarters is a possible solution but do it carefully. Heat guns produce a lot of heat and can blister the paint so be careful if you do that.
What size rims do you have (obviously 17" but I mean width) and what is the backspacing? 275/40/17 should work fine on a 9" rim but if you have 8" or 8.5" then the sidewall may be ballooned out and causing the contact.
Does it scrub anytime there is weight in the back or only on the turns? Jack up one side of the back of the car and check clearance on the other side. If you have clearance, then you may have worn bushings in your rear suspension that allows you to "wag your tail" a little in the turns (body sliding side to side over the rear axle). In this case rolling your quarters will only band-aid the problem. It is worth some additional checking.
 
Alright, I am stock height with stock springs. I have 17x9 saleens and I have no idea on back spacing, I bought them from a local who didn't know either. He just told me the back spacing would work on my car, since they worked on his. It only rubbed with my mom in the back and only on curves that had bumped in them.. straights and drive ways did not rub at all.. I noticed with her in the car and me outside looking, my car looked very low, maybe what you guys look like with 2" drop.. but just on the passenger side where she was.. the other side looked just fine.
 
Sounds to me like tired springs and maybe a little bit of wear on the rear bushings. If you are looking at spending $1500 then you can save some good money with just new springs and good replacement bushings in the rear - heck change the upper and lower arms as well and still come out cheaper. If you prefer the turns, then you may want a little stiffer spring in there and up front as well.
 
Thanks for the info. I really want the maximum motorsports sport kit. That kit has pretty much everything in it I want. Also, I have tried at least 10 different body shops in north central Arkansas and southeast missouri. Not one of them even knew what rolling fenders meant. Is there a more technical term or a more specific type of body shop that does this work? Lastly, if I wanted to replace my rear bushings, what bushings would u recommend for maximum efficiency?
 
Hehehe... You said sex... Lol. Well its a good thing I didn't need em rolled or I would be in trouble.. I hate not having a performance shop or anything around where I live.. the closest I have is some Honda shop that does Honda motor swaps and puts lift kits on the cars with the big rims.. so any input on the maximum motorsport sport grip box? Are they over priced, under priced? I know it comes with a lot of what I was wanting to install.
 
Just for information purposes - what is meant by rolling the quarters (technically they are quarters in the rear and fenders in the front) is to take the metal lip of the quarter around the wheel well opening that extends back in towards the wheel well and bend it up away from the wheel. This is functional but only a band aid for a bad choice in wheel tire combo or worn suspension parts and is much more difficult to undo. I would not on my car but many do. As stated earlier, you should not have to with your wheel/tire combination - it should fit fine as long as the axle is staying where it is supposed to be. If you like the corners so much, positively locating that should be a priority.
As far as which bushings to use, there are may camps on this one and you would be well served to do some research. Main choices are rubber, urethane and del a lum. Rubber is superior for isolating vibrations and taking the edge off of hard bumps. From my experience the urethane give much better feel and feedback from your suspension than the factory or aftermarket rubbers but squeak and are annoying. The del a lum are a better design in my opinion as they are multi-part and act like a bearing (one piece can spin in the other) and a bushing (solid inner and outer sleeve) and are grease able. They are pricey and leave no bump or vibration unfelt but I like them.
Maxim Motorsports is pricey but in the end you get what you pay for. I would not anticipate you having to replace parts from them (non wear parts) as they are very particular about how the products are made and of what material. For bushings, they tend to use urethane (probably because they are already at the high end of market price for the rest of the parts). That being said, you can get more expensive piecing a kit together yourself. Metco makes a killer set of lower control arms that are $340 all by themselves.
Do a little research and make your own choice for your driving style and intentions for the car.
 
You should see the casting flash inside my rear fenders of my car. Though it is lowered with H&R Supersports and I run the 17x9 10th Anny's with a 1 inch spacer. I have 275/40 tires as well and the flash has skimmed the edge of the tread/sidewall a very good amount. I have corrected this by adjusting my MM XD LCA's enough so they don't but the damage is done.

I do have a heatgun from HarborFreight that I use in my Xbox Repair side hobby..haha!
 
Thanks for all the help, especially you lug. Lots of great info put in here.. how would I figure out the back spacing on my rims? I am also looking at getting some sweet dished frs or some one of dished rims.. so I need to figure out the correct back spacing. That way I can also figure out how low I can drop the 96. Once again, thanks for all the great info.
 
Sorry to bump but I'm curious if there's a casting print of the backspacing or if you have to know it from when you order. Also, what will the correct back spacing be for a 17 x 9 and 17 x 10.5? I've searched but can't find a specific number. I specifically need to know what will fit a 96 gt.