JJ Good info. I believe the 4th gen f body pump unit is 11 inches ( may compress more). In the vetteworks online install page, it states "The F-Body fuel pump assembly has about 1" height adjustability". I plan on removing the vent part of the tank just like you did. It looks like a good flat (surface) mounting position and I will use the new pump vent line. Question,did you have any space issues with the new pump or fuel lines or any rubbing on trunk?