Cam shaft suggestions

I have a1987 5.2 carbureted factory roller tappet engine , the computer has been eliminated.( the engine is now in a 1984 D150 short bed pickup) Now using mopar ECM ignition. Need camshaft suggestions due to no bottom end power and timing issues . Want to keep with the roller cam , due to Major cost in going back to a flat tappet cam … any suggestions ?
How many miles are on the engine?