Hot Floor

When cruising after about 1/2 hour, feet start to get warm. The car is a 67 Dart with 360 4spd and factory air converted to Sanderson compressor and 134a. Aluminum Rad with twin electric fans. Engine temp is between 180 -200 degrees and fuel mixture while cruising averages 14.4. The car has a air dam that also forces air to lower part of Rad. I think that with the TTI headers the hot engine bay air has a hard time exiting the back of the engine bay heating up the floor/firewall area. I have already thought of raising the rear part of the hood to let some hot air exit but I have a cowl induction air cleaner so that would then suck in the hot air to the engine. Was thinking of drilling some holes in the inner fender between the shock tower and firewall on both sides to let some of the hot air out, what do you think? Also have finally found the plastic pieces that fit on top of the frame forward of the upper a arm blocking the open space there. Do you think installing them would help or hinder my problem?