If I knew 335 wouldn't require any major fabbing and just selecting the right offsets and rim width I probably would have tried it. But since I already waited two months for these wheels I'll stick with 315's.

Though one thing I've found out about running big rubber out front is that my power steering really doesn't like me going from lock to lock on a tight track. I have a cooler and I'm running synthetic fluid but it's still fighting me making all sorts of noises. Thinking about going with the turn one system as I hear good things about it.

 

I think it's only a matter of time till the PS pump quits. Mine is doing the same on my LT1 car...sounds like a roots blower. I picked up some PSC rebuilt units (1 used and 1 brand new since PSC does not do LT1 pumps anymore) that I need to install this winter. I've had good success using a large cooler and Redline Fluid....both motor oil and PS fluid.

I spoke to Turn 1 at PRI and they do support the LT1 crowd as well as offering new units for LS1 setups.

If you plan on racing for a unforeseeable future in a Fbody, at a minimum (for YOU and the cars health) I would do the following:
Upgraded PS pump + cooler + better fluid
Upgrade front hubs
Race seat + harness
Upgrade your summer motor oil (Redline 10w40 has worked well for me last summer keeping oil pressure up while hot-lapping with my wife at autocross...that sounded dirty)
MAYBE add oil cooler setup if you Road Race