Yup that is a long water pump alright (no room behind the pump for anything with a short pump).
Because there are two water pumps with a set of regular production V-belts and a set of high performance V-belts (heavier steel so it won't bend and they have a deeper grove to capture the belts to prevent them from turning). That yields four sets of possible pulleys with different off sets and diameters. Now think about the BBC; it has the same issues with pulleys, and the BBC pulleys will bolt onto a small block (or vice versa). That is eight different pulleys for any one accessory that could have been incorrectly swapped out over time.
You can take all of your pulleys of and remove all paint to see what numbers are stamped on them and then check a matrix to see which pulley goes on your car or you can buy all new billet aluminum pulleys with the correct matching brackets (there are four sets of brackets for every accessory) and not worry about alignment ever again. In fact upgrade to a serpentine belt drive (requires a reverse rotation water pump with some applications) and forget about slipping or thrown belts.
Or for a fraction of that price strip off the accesories and brackets and pulleys off of a scraped out 305 enroute to Korea. Most of the big salvage yards around here offer an all you can pull and carry for one price on a Saturday morning. (either $99 bucks for anything you can drag off yourself or by the pound buying it at scrap metal prices, which makes for a lot of sore backs on Sunday while watching football).