I have two ports coming out of the side of the LS1 water pump. One is larger than the other. I need to know which one is the supply and which one is the return. I am installing the Vintage Air system and need to know how to route my hoses. Any help would be greatly appreciated. Thanks

 

tsnow, this should help!
https://ls1tech.com/forums/conversio...-question.html

 

Small outlet is supply, large outlet is return

 

You are the man! Thanks that was a big help!!

 

Thanks lizeec!

 

Awsome, good info to know

 

x2...

 

most system will usually be small is pressure and larger is return. Take a look at your radiator, power steering and AC system.. Easy to remember...

 

You know I never put the connection together before starting this thread. Its funny how you change out all these lines over the course of years and never realized why one was larger than the other. Thank bczee and all of the others that helped out. I have my routing solved onto the next issue!!! Thanks again