Multiple bilge pump holes on one side - proximity

[keith]

I have a '72 23' SF and I installed 2 2000gph rule pumps. One pumped to port and one to starboard. I would like to leave the existing 450gph that is wedged in at the stern under the oil pan to remove excess water out of the bilge after wash down. My question is about drilling another hole in the side of the boat that will have to be within 4-5" of the existing hole. Is this ok? How close is too close?
The existing hole is for 1 1/8 id hose and I think it is 1 3/8 hole and the other pump would be a 1" I think.

Thanks for the advice.