lobe separation angle

i have built a few 340's and no denying a mild 340 is a perfect fit for a well balanced all around performance A body street machine.Not too much torque,excellent launch,quick revving,good mileage and pulls hard from 1200 to 5200 rpm...
But...i think my next project will be a Teener so i'm trying to figure out exactly the best all purpose combination...with an emphasis on silky smooth idle,good torque,handling and mileage...