Dougs headers

It feels like the engine and tranny need to move back an inch. I had to push the motor and tranny forward to get the motor mounts to set into the k member. I also could not get the fan and fan clutch to fit because I needed about another inch to get the clearance I needed. Could I have the wrong small block motor mounts or is there just one style? I would like to get it figured out before I take a hammer to a new set of headers. Thanks, Todd