A RA III is alot of cam for a 350 with 2.56's and an auto. If I recall correctly pontiac used those in stick cars with larger displacement and probably higher compression. You can run what you brung and it will run but from what I have read so far about what you want, I'd look at a smaller cam. It's just going to be lazy with the 2.56 gear until it's rev'ed up. I think cruising will just be more fun with more throttle response at your cars typical rpm with a better matched cam.