front end rub problems

[dirtybird]

I purchased Hotchkis TVS kit with 3 inch drop springs for my 68 firebird. Engine is a 461 stroker with aluminum heads. When I called Hotchkis they said I need to use the small block springs part# 1937f. However, this is not working with my current wheel setup up front which is 235/40/18x8. Wheel backspace is 4.75. Any bump I go over it hits the fender. I know that many people run that combo, so I'm looking for advice on what you guys are doing to make this work. My thoughts are to either adjust my shocks (varishocks) to the stiffest setting, get 225 tires, or change to the Hotchkis big block springs which are only 2inch drop. My front suspension is otherwise stock. Any insight would be appreciated.