NC_John

iTrader: (1)

So I got a new GM/Delco water pump for my 6.0 build. PN 251-743/ 19256261. I also got a 180 degree thermostat/housing from Summit (their PN SUM-363-180). The new thermostat does not fit the new water pump.

The ID of the water pump thermostat opening is (approx)1.866". The old thermostat (where it enters the pump) is about 1.667." The new replacement thermostat measures 2.040" so you can see the problem.

I am confused over some changes that were apparently made by GM (lingenfelter site has some info but didn't help)that has got sizes mixed up. I am not keen on grinding the new pump to fit so what thermostat with housing can I get that will fit???

thanks

G Atsma

Is the water pump a different model than what came originally on the LQ4?

NC_John

iTrader: (1)

I ordered the water pump through GM and it bolts up fine, plumbing connections are all good. Unfortunately, I don't have the old one any longer to compare. The original thermostat bolts up ok but the new one is too big. The housing is OK and fits but the thermostat diameter itself is bigger. That is what came up through summit for an 04 Lq4. I hope to find/get a 180 degree thermostat and not have to get a factory 186 from the dealer.

NC_John

iTrader: (1)

I think I am overcomplicating it. I didn't think the thermostat came out of the water neck but it did pretty easily. I'll just match up the dimensions to one on the lingenfelter site and I should be good.