Wanted to know what the largest size tire is, and the widest possible rim as well for 18's. Some say that 11.5 is the widest you can go with 18's, but ive also heard that a 12 or 13inch wide rim will fit on our f-body's as well. As for tires, how big can i go... 295, or 305 ??

Keep in mind that the car will be lowered as well with long-tubes.

Thanks guys.

 

In the rear you could go with a 315/30/18 on a 18x12 inch wheel. On the front you might be able to get away with a 295/35/18

 

Up front i would like to have 18x9.5's, but in the back it will depend on the fenderwell i guess. Do you guys see any possible problems with a 18x12 rim and a 315/30-18 tire wrapped around it on a lowered LS1 ??

 

This has been an ongoing question for me but with 19" wheels. I want to run a 335/25YR19. Some people say It will work with rolling the fenders and a little hammering of the inner fender wells others have told me "No way no how" and others have said they will bolt right up.
If I find out anything I will post back and let everyone know.

 

I'm going to run the following in the next 2 weeks, Forged OEM Y2K Vette wheels, 18x9.5" in the front with 275/35/18's and for the rear I'm running Widend Y2k's to 18x12.5 running 335/30/18's(13.5" wide), it's a bit of work but with 3" wheel studs(on my Moser 12 bolt), a 1.25 billet spacer, rolled fenders, beat in inner wells, and custom LCA's to offset them to the inside .75" for more clearance- it'll all fit inside barely, sounds like a bit of work- depends how serious are about doing it, any questions e-mail me.

 

Formulation, the stock rear end and the Moser are the same width arent they? The 1.25" spacers are for back spacing issues and the 3" studs are being used to compensate for the 1.25" spacer right?
When you get them installed will you please email me some pics and let me now if you have any clearance issues? What brand of tire are you using?
I am wanting to run the 335 on a 19" wheel and have been unsure about fitment. Please keep me informed

 

The widths are the same as the rear ends go, and yes I had the 3" studs pressed in so I could use hub centric 1.25" spacers instead of the off set stud type for strength, I could have gone with 1.5" but that doesn't leave much lug nut engagement, ARP makes Nascar style 3.5-3.6" studs, if that is needed you can go that route, I'll have to measure the backspacing, tires are Michelin Pilot Sports(stock Viper sizes all around), the others available are Pirelli and BFG, I got a great deal on 3 sets so I should be good for awhile, oh the actual outside edge to edge of the rear wheels are 13.5", it's 12.5" at the tire seat points, the 335/25/19's have an overall height of 25.6"- a little shorter than the 18" 335/30 at 26-26.1"- this is where I like it at, also the 19" a bit narrower at 13.2 on a 12" rim(fit 12-13" rim) on a 12.5"(13.3 on 12.5"- preferred) still plenty wide, you will or should have to roll the fenders and check the LCA clearance, this can be a limiting factor-I got around that with the special ones, the other points of contact will be the front area of the inner fenders above the LCA's and the area around the springs on the inner fender-you will have to do some grinding where the top "rib" is in the spring area on the inner well, it will contact at the widest part of the tire. good luck hope this helps, I spent alot of time getting this sorted out, e-mail for further questions.

 

Formulation, thanks for all the info <img src="gr_stretch.gif" border="0"> Please let me know the measurements for offset and backspacing if you have them. Pics would be great when you get some. Thanks again!