I am having my 1968 428 rebuilt and thought (guessed) that I had an 8 bolt water pump. I went and picked it up to repaint and figured out it is a 69-70 cast propeller and pump and matching backing plate and timing cover. To my surprise someone has already swapped it to an 11 bolt! It looks to be in great condition. I have no idea how well it works since I only have about 30 min of driving time. Should I go ahead and install a flowkooler or just stick with this one and modify the backing plate to fit a little closer to the impeller?