I too , am trying to learn about Olds engines . I`m afraid i`m not much help on your questions, although, i have been told cams will interchange. I simply don`t know that for a fact. I have been into Chevy for ever. And i do beleive there is no better street carb than a 600 cfm Edelbrock( for most of us low buck guys) I do think the 600cfm is too small for your 455. I think the q-jet that came on the 455 was rated at 750 cfm stock. I can tell what i do know!!! Two things The headers will interchange between small and big blocks, and 2) you are now on the best site there is. Some one on here will answer up for ya. Mean time welcome to the board!!!
Slider in Wa.