FastKat

iTrader: (10)

I have an LS1 water pump in my hot rod and the water neck interferes with my fuse box. I was looking at the S&P catalog (where they have LS1 and LS3/LS9 water pumps lined up next to each other) and it looks like the LS3/LS9 water neck points to the 7 o'clock position, where the LS1 water neck points to the 9 o'clock position. That little bit should be enough to clear my fuse box while still using my existing lower rad hose.

So the question is, will an LS3/LS9-style water neck work on an LS1-style (early Corvette, Camaro, Trans Am) water pump?

KENS80V

iTrader: (16)

The difference is the machining on the inside for the thermoststat. In fact a LS2/early LS3 (05/08) is not the same as a LS3 (09/10) t stat housing. Some owners didn't know this and have been having leaking issues when they switched to a 160 degree t stat.

-Joseph-

iTrader: (12)

Yep, different. Also for reference, the 2010 Camaro L99/LS3 water pump and all accessories have the truck belt spacing away from the motor.

FastKat

iTrader: (10)

On my LS1 water neck/thermostat assembly (which is the early style that was used on the 97-04 Corvettes and all the F-Body cars) the mating surface on the water pump is flat and the water neck assembly has a groove in it for an O-ring.

What does the mating surface on the LS3 water neck look like? (Whichever one has the 7 o'clock outlet, as opposed to the 9 o'clock outlet on all the LS1 and LS2 engines)

As long as the LS3 water neck is designed to mate to a flat surface, and the bolt pattern is the same, this should work. I would probably have to buy an LS3 thermostat, too, but that's fine.

Petraszewsky

iTrader: (28)

It's a flat mating surface on the LS3 pump...I sold one awhile back...