If there is a rubber trim piece between the hood and firewall, you might be able to cut or remove a section of that, in order to allow some heat to flow out while driving. However, you have to be driving over 40 mph in order for this to work and MAY only reduce engine bay temps a few degrees. I would follow Turbocharged400sbc's advice and check the actual radiator for dirt/dust and shit clogging it.
If that is clear, then go ahead and check the cooling system and swap out the thermostat for a lower temp. Typically, in the summer, I run a 160* stat, while in the winter, i run a 195* stat. They should be fairly easy to swap out (or at least on every car I've owned they were).
Last but least, check the wiring to the electric fan to make sure that's working. It should switch on and off even while parked to cool the motor. If it doesn't even go on, consider yourself lucky to have found it before something goes BOOM!