Take the air horn numbers and look here. https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://documents.holley.com/techlibrary_carb_numerical_listing.pdf&ved=2ahUKEwibjqCNlYWAAxXHnWoFHX0QA_YQFnoECBkQAQ&usg=AOvVaw1UziVPwG2-N82hs9EiLZMZ
Lube impeller with either a drop of dish detergent or a drop or two of water soluble glycerin such as KY jelly
If your in the water, the pump is below the waterline, so it will self prime
The thermostat housing has 2 1" outlets, the big lower hose connection, and the 1-1/4" inlet from the raw water pump . One outlet should go to each manifold. The manifold exits thru the elbow to the y-pipe.
