[Regal Beagle]

Can anyone help me by telling me what size NPT fitting I need to run off my Edelbrock Victor waterpump and Performer intake to hook up my heater hoses. I have called a couple of the speed shops in my area and have one guy telling me 1/2 inch and another 5/8.
Your help as always is appreciated.

[BBCMudbogger]

You need to find out what the NPT sizes are from the water pump and get the corresponding AN size they run in 16ths..... in other words 4an is 1/4" 6an is 3/8" and 8an is 1/2" and so on .......you will use a NPT to AN fitting whatever NPT size the pump is tapped for to hook your AN fitting to.

[KA67_72]

http://www.mcmaster.com/#stainless-s...d-pipe/=2a0e2a

In the middle of the page it tells you how to measure NPT fittings.

Kevin

[Deez]

in other words 4an is 1/4" 6an is 3/8" and 8an is 1/2" and so on

IIRC, you can take the AN number, like 4AN and divide by 16... 4/16 = 1/4, 6AN 6/16 = 3/8, 8AN 8/16 = 1/2. Same deal, just a different approach.