Is it a CSR water pump? CSR swears they are good for 50,000+ miles. I'm planning a nationwide road trip as soon as I get all the bugs worked out. Maybe I better bring a spare motor...
I also have some questions and comments about your swap:
What did you do about the motor mounts? Are you using a tube cross member from BMR or otherwise made for small blocks? Or did you decide to take your chances with 2 out of 3 bolt holes?
(I thought about it for quite a while)
Have you, or are u planning on making a rear support bracket for the alternator and A/C compressor? I'd like to see what you made if so.
FWIW, I was able to use the LT1 radiator with no problems. Engine cools fine and I have heat.