The cam I used in a 400 which was low compression was the 474 purple shaft, 110 lsa, sounded great & worked with the original converter, was in a 73 charger se, in high school (1997). That cam had 230 something (238?) duration @.050, id look at something like that, not a purple shaft for the wallets sake, and for longevity sake hydraulic roller. In the 234intake -238exhaust to help get out the manifold.
Should be able to boil em. I personally like howards cams.