Choosing a cam

I am building a mopar 383 and need help with cam selection. I am trying to find a hyd flat tappet. The Engine has flat top piston that don't have valve reliefs and sit at zero deck. The heads are 1968 250 castings that have 2.14/1.81 valves and have not been shaved. I will be using .02 head gaskets
I am looking for a cam with good lift, but not enough duration to cause a valve to hit the pistons.
It will have 9.5:1 comp, 3000 stall, 3.55 gears and weigh 3700lb
I have a 509 purple cam with 292duration and 108lsa on hand, but I believe that it will be too much for those pistons without valve reliefs.
Thank you for any recommendations.