Just was wondering if the thermostats from 98-2002 were all the same for the LS1's. Just picked up a 160* Thermostat from Hypertech and it won't fit in my 99 Trans Am. I took my factory one out and the thermostat just pops out of the elbow and has narrow clips that hold the thermostat. The Hypertech one has alot wider clips that hold the thermostat and it wont even go into the housing on the engine. Its about 1/4-1/2" too wide but the part numbers say it will fit the car. Any Ideas? I wil also load up pictures.

 

Sounds like you have an LS2 pump on your car.

I ran into the identical problem on a car last month (2002 Fbody), and come to find out it had the pump replaced with the newer LS2 unit. If your thermostat is a two piece, then you have an LS2 pump & stat. Summit sells the stat for around 20-30 bucks I believe.

 

Thanks!! Here is the pic of the Stock GM stamped Thermostat Housing(left) and one of the Hypertech(right). Time to look for a LS2 Thermostat now.

 

Anyone need a 160* Thermostat for a LS1 for $30 shipped never installed since it wont work for mine now.

 

Yep thats def an LS2 unit.

 

This happened to my buddy...

 

yeah it really does suck. pulled of the thermostat and had coolant all over the place. went to put the other one on and doesn't fit. Now car is sitting in the garage until I get the LS2 Thermo.

 

I got one of those hypertech 160's it didnt fit with the housing it came with I guess so my buddy just stuck it in the stock one and it worked I think thats what he did

 

upfirehawk.. let me know if this fixes yours..I ran into the same issue with my 2002 SS

 

Yeah Just put the 160* Thermostat in for a 04 GTO LS2 and it fit perfect and works great!

 

good news! thanks!

 

I ordered the LS2 160 theromostat from Speed INC. Got it and put it in yesterday. It worked! Thanks guys!

 

can anyone tell me what the benifits of going from the stock t-stat to a 160 stat in a 99 ls1 would be? just picked a 160 stat up but not to sure if i wanna put it in. thanks