American Psycho

Just wondering if people upgrade their water pumps when going all out on a heads/cam setup. My stock pump really hasn't had any issues, but it is getting up there in age. The LS2 pump looks like a good, cost effective alternative, but is it a direct bolt on fit? Thanks for any feedback.

Mercier

iTrader: (15)

I'd like more info on this as well. I am about to slap my LS1 water pump on an LS2 and need to know if I will have problems or if there is enough advantage to a proper LS2 water pump to make the purchase. I have a new LS1 water pump as O'reilly gave me a warranty replacement.

redbird555

iTrader: (14)

pretty much anytime you go to get a replacement wp its going to be the ls2 style as the deisgn has been replaced. it bolts right up but will require a different thermostat housing. the ls2 pumps flows more than adequate also if thats what you were asking.

i run a meziere on mine and its great but i got it for a good deal as they are quite expensive brand new

Mercier

iTrader: (15)

Thank you for the info. So I will assume I got the later design. What is different about the thermostat? I did get a "warning" sheet in the water pump box that indicated I should use the o-ring for the earlier-style thermostat housing and just the flat paper gasket for the later-style. Are there other differences? It seems that I have the earlier-style(new) tstat housing with the o-ring and it seems it will fit fine and not leak. I would rather an o-ring seal personally. I could easily return it and get the LS2-style housing. Any reason to do so?

Thanks again for the help!

01MAROONz2890

nope lol if the thermostat fits then its fine. the older style physically wont fit into the new style

Mercier

iTrader: (15)

Got it. For the record, I brought my O'reilly water pump back and compared the 2005 Vette tstat housing and both would fit. I guess the reman companies are making a hybrid that fits either way.

Thanks again.

FU_I_AM_UltraZ

iTrader: (20)

it's already an aluminum housing... just run a 160 t-stat and change the temp for your fans to come on at... wha-la!

American Psycho

So if upgrading the water pump, you must purchase a new thermostat as well? Or just the housing?

Mercier

iTrader: (15)

You don't have to replace if you don't want/need to, but I wouldn't change a water pump without changing the thermostat. They do wear out eventually. You can go with a lower temp thermostat(160 degree) and set your fans lower as UltraZ mentioned above or get the factory thermostat which is about 18x degrees. FYI, the thermostats and housings at the parts stores I have seen(I had them pull a 2002 Silverado 5.3 as well as a 2005 Corvette LS2) were sold as a unit but you may be able to find aftermarket thermostats without the housing. At O'reilly they are between $30-$50. The housing shouldn't wear out, but you would want to match housing to water pump.

ls1 1990 VN

Fit the GTO LS2 pump, it will also allow clearance should you wish to fit the Fast 102 intake without having to grind anything.