I,m about to get some new wheels and I plan on doin some autoxing,and was thinking about 17x9.5 in the front and 17x10.5 in the back.My question is about the handling. Should I get the same width all the way around, or does it make a real difference?

If you're only going to do one or two autocrosses per year, or if you aren't on a budget, get the big-n-bigger setup. If, like me you are on a budget and can't afford a dedicated set of racing wheels and tires, get all four the same size. Autocrossing wil brutalize your front tires, and it's nice to be able to swap the fronts with the rears to keep from having to buy a new set. The shoulders of the front tires are the first things to go, while the rears don't get worn down much at all.

If you are at all serious about getting in to Autocrossing, get a hold of a copy of the SCCA Solo2 rule book, before doing any more mods. With a 383, you aren't going to be elgible for F-Stock, or E-Street Prepared classes. You will probably want to run in Street Modified. SM is a class for modified street cars, without getting in to the full-race machinery of the Prepared and Modified classes

The SM rules limit engine size to 6 liters (366 c.i.) and it has to be a street production block. This would only be an issue at Nationals or maybe Regionals. At the local level it is unlikely that someone will through a snit.

Yeah, I need to take my own advice and get a new copy of the GCR. Mine's like 3 years out of date.

Most local events are pretty casual about car classification. We made up a class (O-street prepared) so that a guy could run his lowered Chevy C-10.

Thanks for all of the replies. I'll check to see if I can get a copy of the Solo 2 rulebook at the SCCA Website? If not, anyone know where to get one.
On another note, What suspension mods have you guys done. This is what I have done. A wonderbar, PST bushings( I have an Eibach Pro kit That I haven't installed yet)and KYB gas adjust struts to the front,KYB gas adjust shocks, Spohn LCA's w/relocation brackets,Adjustable panhard bar and Torque arm , also from Spohn, attached to a custom 9" rear. I also have an 8 point roll cage and sub frame connectors. I think I'm pretty good with the back end, but the front end I think still needs some work. Any sugestions?

Koni Sports front & Specials rear, SLP 1LE trailing arms, Edelbrock pan hard bar, stock springs, poli bushings for stock sway bars, Global West stearing brace, Strut tower brace going on this week.

I run ESP.