Where to buy - "smooth" water pump with 8 holes ?

[Green Machine]

Trying to find a "correct" short style water pump for our 1971 C20. The old pump has the "smooth" casting without the extra outlet on top and the hub has 8 holes. We need the outer larger pattern holes.

Only thing I can find with the larger pattern has the extra outlet on top. I have checked several sources and all the smooth ones have four holes with the small pattern. Now if the old one had 8 holes and is smooth, why can't I find one like that ?

I could buy a rebuilt, (new ones all seem to have the top outlet), and press the hub from the old pump onto the new pump, but the threads in the old hub are almost shot, looks like someone tried to run fine thread bolts in there(not me).

Any suggestions ??? I really would prefer a new pump if possible.