Reply to "Group 4 wheels spec"

Jack,

For my GP4 I used the same backspace as my GT5 (the same 10x15 and 13x15 Campi's were used);

10x17 and 4.625" BS
13x17 and 4.75" BS

Two things worthy of note;
1. different wheel suppliers quote backspace differently, BS quoted above is to tire bead lip
2. More important than wheel dimensions is the flares, whether steel or fiberglass and supplier, as there are most certainly a number of variants offered. Fiberglass flare fitting is somewhat predetermined, but steel is very dependent on the fitting process as most need at least some metalwork. For a comparison I'd recommend dropping a plumb bob at the outer flare lip and measure the distance to the hub wheel mounting flange.

Tires for front are 275/40/17 and rear 335/35/17

The 'find' function can help you find some more previous threads on the subject;

http://pantera.infopop.cc/eve/...=634102565#634102565

Even with an 11" width rim you would probably want a 335/35 tire to get the right look and the rim will be seriously offset to fill the flare. FWIW I ran the 335/35 on a narrow body car with 11" rims.

Julian