None of the first generation Birds ever had an insulation pad. It is a very bad idea to consider one. For one thing, it may be so close to the carb air inlet that it would act somewhat like a choke and perhaps enrichen your fuel/air ratio. At the very least, it would make for a dandy dust reservoir collecting dust that is just waiting to get sucked into your carb. You can't hardly beat nice clean paint on the underside of your hood to keep from contaminating the air supply into your carb. I even keep my hood scoop block off plate permanently installed.
Tom
