I have seen very few 67-68s with heater delete. It is depicted in the assembly manual (C48). The photos of Grumpy Jenkins '67 L78 car show it as does the body tag. It was a "credit" option, you saved a few bucks.
Due in part to dealers complaining, for the 1969 model year the Feds mandated cars built for the contiguous 48 states have heaters. This leaves out Hawaii. There is a '69 Z/28-RS around here with C48, built in LA, sold new in HI. Probably Camaros bound for Canada could have have had C48 although it is known to get cold up there.
Radio delete is a confusion in terms as a radio was not standard equipment. But it was tough to order any sigificant number of cars without radios as it would prompt a visit from the Zone, who would threaten delays in scheduling. Larger dealers could get away with it and many would then install an aftermarket unit usually Motorola, to add a few bucks profit. I still have a pop from a friends '69 L78 car, no radio shown.