Several years ago I weighed some SBF parts on a 351W when I was trying to shave some weight the numbers will be close for a 302.
Edlebrock Aluminum heads saved 25 pounds per head (50 pounds)
Edelbrock aluminum intake saved 40 pounds (will probably be a little less for a 302. say 35 pounds)
Aluminum water pump 7 pounds
AFB instead of Holley 5 pounds
Headers and stock early style the headers actually weighed 4 pounds more although they were full legnth headers. Shorty headers would probably save a couple of pounds.