Exhaust system for 383 stroker

[stringpickin]

Hello and good day.. Question, I appreciatte the responses. I have a 70 chevy 4x4 with a 383. I put a mild crane cam in it just above the torquer level for most custom cam setups for truck engines. I need a new exhaust system. I used the original 2" system for the last 7 years. I have been told that I should go to 2 1/4" pipe. I am concerned because I have always heard that with trucks if you loose the back pressure, you will lose torque.. Looking for user/or exhaust pro qualified input on this question.. Another place recomended that I go to a performance 2 1/4" dual to single muffler exhaust system with a 3 1/2" single exhaust to improve torque.. What do you think. Appreciatte your time.. thank you..