Yeah, I would fatten up the mixture first. Then I'd be looking at the fan. Is it an 18", 7-blade design steel fan like was used OEM? Are you using a fan clutch? Is the fan turning at least 1.2 times crank speed? Is there sufficient space for hot air to exit the engine compartment?

On the off chance that you're using an Edelbrock, here's the Owner's Manual so you can figure out the tune....
http://www.edelbrock.com/automotive_...ers_manual.pdf