View Full Version : Heater hose fitting on LS1

04-19-2011, 06:10 PM
I am trying to find out if I can install a 45 degree 1/2" NPT to 5/8" hose fitting and a 45 degree 3/4" NPT to 3/4" hose fitting to a LS1 water pump. How hard is it to remove the factory fittings and what size are the holes when you remove the fittings and has any one done this. I am trying to make some clearence so my heater hose does not rub on my upper A arm, any suggestions please let me know, thanks

04-19-2011, 06:19 PM
It's easy to pull the stock nipples of the water pump, and the holes are perfectly sized for tapping with a pipe tap. 3/8" and 1/2" I think.

04-19-2011, 06:53 PM
Yep I just tapped mine to put plugs in 'em. 1/2 and 3/8 npt.

04-19-2011, 06:55 PM
On second thought just go to the parts store and get some molded 90 degree heater hoses. That will take up less space than fittings and be WAY easier to install


04-21-2011, 05:26 PM
my buddy Tim at [coast chassis] just did that swap on my ls water pump tapped both heater hose fittings and tigged a 16 an fitting on the upper hose for rad looks very clean

04-21-2011, 06:10 PM
I went with a 90 degree formed heater hose worked out great thanks for the idea and I will put pics up after it is finished, thanks again Rich