Installing one wire alternator

OK guys, am in the process of installing the new alternator, and once again, nothing is ever easy.

Have pulled the old AC Delco off, and have replacement powermaster one wire square back to fit this engine. Also found, ordered and have replacement alternator bracket that should fit this engine. Not having ANY experience with this engine, it took hours of looking to figure out how it was supposed to mount up. Pretty sure I now know...........and that is when the trouble started.

Looks to me like the base bracket is supposed to fit thru these two holes.........(sorry iphone camera truely sucks in low light).......

IMG_1822.jpg

So top hole has an existing bolt......which I believe is going to be long enough to run all the way thru to the engine block.......about 5 inches or so thru the water pump. Bottom hole and bolt should be the same, except it isn't. Hole bottoms out about 1/2" in. My guess is there is either a stud in there, or a bolt that has been twisted off. Either way, there is no way to bolt the bracket up as is.......so looks like I get to pull the water pump to find out. When I loosened the top bolt, antifreeze started leaking out, so to even pull that, looks like I need to drain radiator. All this just to swap out the alternator to what should have been there in the first place. :mad:

So questions are..........am I right to think there are two 5 inch or so bolts needed to bolt bracket base to the water pump? If I pull the water pump, is there a rubber or other gasket that has to be replaced?

Also, when ordering bracket, choices were cast iron (pre 70's) water pump or aluminum (1970's and later). I went with aluminum.........does that also look right?