I agree with the intake beign a restriction,there are also better cams but thats in the ball park and should be fine,and as others said cehck/update the ignition.One thing not mentioned but directly relates to your e.t. is your convertor.Any off the shelf convertor is suspect and most are flat out junk,they never stall where they should and most are too tight.At 103 mph Ive ran 12.90s at that speed so theres some losses in your drivetrain.