ironmikektm525

Bought my 99 t/a with some mods done already. Thinking of doing the 180 stat. Dont want to drain fluid to find out its already done. Near the top housing mounting bolt there is a small stamp of what appears to be the sun with lines all the way around it ? Yes the sun up in the sky. Is this a factory housing and is there anyway to tell factory housing?🌞 basicaly looks like that pic just a hair bigger. Any info would be great. Thx

RPM WS6

iTrader: (3)

I don't recall what the difference is in terms of external markings between the stock housing and the aftermarket 160/180 t-stats. However, if your plan was to do a 180° then you might as well just save the cash and keep the stock one, since it's a 187°F (86°C). Those seven degrees aren't going to make any real difference.

ironmikektm525

Stock is 187? Thought 195? Done a bunch of reading and 180 seems to be the choice over 160? Was gonna do 160 til i read all the neg feedback. Your thoughts? Water waetter do anything? Thx

RPM WS6

iTrader: (3)

The assembly line original T-stat that I pulled from mine (bought brand new) was stamped "86" (C) on the bottom. 86°C = 186.8F.

EDIT: On the bottom of the housing is a GM stamp and part #12567563.

I would recommend the 180 (or stock 187) over the 160 as well. But there is little reason to go from stock to a 180 unless you just happen to need a new t-stat anyway.

ironmikektm525

I see what your saying. I'm always looking for that little extra no matter how small it is lol. I'm thinking of deleting upper rad hose(power steering cooler style) to install straight hose. So I'd do both at the same time