[colby]

Straight from the GT rules, modified is basically the same.


FIREWALL
The lower portion of the OEM firewall may be replaced with steel
of equal or greater thickness than OEM. Chevy Cavaliers, Pontiac
Grand Ams and Sunfires, and Ford Escorts may have firewall
replaced or relocated, provided the measurement from the rear of
the radiator core support to the firewall is 34 inches maximum. For
Chevy Cobalt the radiator core support to the firewall is 33 inches
maximum. For all other vehicles, firewall must be in the original
location. A complete one-piece steel firewall that resembles OEM
must be installed, welded in place, and sealed from the driver
compartment. The firewall must extend to and attach to the floor.
The firewall and mid-plate must be two separate pieces. All motor
plates, mid-plates, etc. must be separate from and may not be
attached to the firewall.

If you look at the stock firewall, there is no way to keep in intact and do an RWD conversion.