I just installed a new 347 the following E cam stock heads with roller rockers stock upper and lower manifold with 1 inch spacer 24 lbs injectors 155 fuel pump adjustable fuel regulator set at 39 psi 24lb 76 mm c&l mass air meter and k&n cone 65mm throttle body.When i get to 3 grand it goes flat no power i have to back off to get power. Could it be vacuum or computor problem