Could you do something like this? Block off the grill, take sheet metal and run it down from bumper to splitter the "duct" it all into the rad.. even on the inside. This helped our Chump car. Looks goofy I know but it does help. we also pulled the back of the hood up to help vent, I know you're not looking to bend up your hood, but getting some of that hot air out can't hurt.