boggs bad

it was so bad when i got it that i could not spin the tires at all. Then i cleaned the maf then i could not stop them from spining now its getting gutless againg i changed the fuel filter cleaned the maf again new plugs. wires,cap,button all look good nothing helped get weaker every day help me plz

i got a rebuilt 302 with several mods nothing serious like turbo or supercharger. basic run through what i have a edlebrock rpm performer intake larger headers short tube style h pipe with flowmasters f303 cam 351 windsor heads with lots of machine work under drive pulleys ac/smog delete 24lb...