171cc bbk for gy6 mods

[Snowmanhat]

New here, installing a 171 cc big block kit in my tao tao GY6 150 cc scooter to get Better top speed. I geared up to 14/38 tooth but need more power to make use of those gears. What is the best carburetor mods and exhaust mods to support the 171 cc for average conditions. i’d like to keep the pipe as quiet as possible Thank you very much for your help.