Found my dads original 1971 duster!

Ahhh. I’ll have to look up that seal. I don’t think I have one. Did they come on the cars originally?
Yes they had them originally. I bought one recently from Detroit Muscle:

Mopar A Body 67-69 Barracuda & Dart, 70-71 Duster Hood to Radiator Seal with SS Clips

There is also supposed to be a seal on rear of hood to seal hood to the cowl. That seal is important cause it keeps water from getting on bulkhead connector when you wash the car