1. Take off your headers and have them ceramic coated.
2. Take out your interior and add a thickunderlayment like dyno mat and then your sound deadner and then your carpet.
3. Crawl under the dash and inspect the firewall, plug any holes that are open direct to engine compartment.
4. Roll down windows
my carb was running very lean and caused a great deal of heat in the passenger compartment...fattening up the idle speed mixture helped to reduce the amount of heat in the passenger compartment. the other suggestions are accurate as well... just my .02. good luck, Todd P.
tinted windows keep the sun out really well.. get limo in the back and rear side windows., and one or two shades below that for the other windows... youl be surprised how much it will cool down the inside of your car.