I have a 1977 Cutlass Supreme Brougham with an automatic th350 and 5.7L 350 engine. It has been brought to my attention that I will not be able to run headers and true duals because I have a single hump crossmember, and a dual hymp crossmember is needed for this type of setup. Is this true, and if so where can I purchase a dual hump crossmember from?

 

you'll need a X-member for your factory TH350 from an earlier "A" body, earlier than '75. the real question is: in order to run true dual exaust in a post '74 Cutlass, do i need two catalytic convertors? can i run two of them? if so where do i mount the second? do i need to have one of them? can my original one be removed? i suppose if your '77 is smog exempt and the convertor can be removed and not replaced then find a X-member from a '73 or '74 that came with dual exaust, you can source one from a buick regal, or pontiac.