[Marmon4x4]

Just pulled out an old Winfield SU1A that’s been on the shelf for the last 45 years and though It might be worth putting in a 276 I’m getting ready to build for my 38 sedan. Sent it to Isky to get profiled. Came back with a card with info. Want to know what to expect if I use it. Will be running 59AB heads, stock intake and carb, Harmon and Collins dist, Fenton headers, mild porting and port matching. Duration @ .020 270 intake. 258 exhaust
Cam lift .370 intake. .350 exhaust
Duration @ .050. 240 intake. 230 exhaust Valve lash. .016/.018 Will idle be excessively lumpy? How about low and mid speed drivability? Any help will be much appreciated