Did you build the motor? If so di you degree that cam in the motor? If yes look elsewhere. If you didn't degree it and use a Cloyes timing set it may have the dor on the cam gear wrong which makes the cam retarded when you align any of the three dots on it without verifying the actual lobe separation angles on that cam in your motor
I've learn that lesson more than once from three different cam grinders
I degree every new cam and timing set now
Retarded cams have no bottom end and very little mid and top end power