308 Diverter Valve R&R

I am working with a 1978 308 GTS carbed US car. The diverter valve is stuck in the open position and the exhaust "pops" on de-acceleration. Spent most of the day visiting several parts store with my old part. The best I could do is a part from NAPA that should work but will require modifications. Has anyone else had any luck replacing this part? Also is it possible to have this part rebuilt? Any suggestions where? I live in California and have to deal with smogging the car every two years and would like to rid of the popping sound. Thanks much.
Dan

 

i thought the valve was GM and that one for a 305 camaro would work with no mods needed. did you look in the 308 part threads ?

sorry i am not much help, i am exempt from emissions, but i do have a big box somewhere with old air pumps and pulleys i have taken off. it will be tomorrow afternoon before i can dig through them, and see if there are any part numbers for you.