I just put a new GM water pump in my 99 TA with an LS1. Apparently the water pump I bought is for the later style LS1 (2000-02?). The major difference apears to be at the thermostat housing. It has a longer neck where the radiator hoses attaches at the thermostat housing. It also is missing a tang that acts has a wire hold down. Everything seems to fit OK. Am I going to have any problems related to differences in this style of pump? If I am can I cure it by replacing the theromstat housing to the original style?

 

the model you bought replaced the previous model of water pumps, look at the back of your stock one and if you can look at the back of your new GM pump, should be different everything else should work though

 

It is the same as an LS2 WP so a LS2 T-stat housing is needed......