Intake to water pump hose for air gap intake??

Thanks for the replies. It does look bigger than 1/2". I will try 3/4" and see if that works. The car is a 74. The motor is a 73. I purchased the water pump from Mancini and told them it was for a 73, so hopefully all is good.... I have the hose already, just need the fitting...

chubsgts - yea i goto that home depot usually. i was there a few times this weekend... I'm near 12 and Van Dyke, so yea probably close by...