as far as the hp or mpg thing goes guys your about right with my thinking too, there isnt really no difference i would think, the reason im looking at the swap is to "clean" up the mess, and as well to be able to fit an aftermarket choke assy to my spreadbore holley carb thats on there now, so i would have a working choke, this is not a swap for hp or nothing like that , it is to clean up the look of the motor and to give me a working choke assy.
i have found that weiand makes a 8017 intake for peanut port bbc heads, i didnt think the performer 2-0 matched very well to the peanut ports...........i thought that intake was for the big ovals likes the 290 heads, it has been awhile since i had a performer intake and i guess i didnt pay much attention to the ports back then.