Hi all.
I have a buddy that has a 85 vette, He wants to know what is needed to replace the thermostat on it.
Does the throttle body have to be removed?
Any other parts on the block , hoses, brackets ect...
Draining coolant required?

I tried finding a video. No luck.
I told him i could help him, but not sure myself what to do.
I have no experience with the C4's so any help is appreciated.
Thanks in advance.
Joe

Taking the throttle body loose from the plenum would give ya more room, but I don't think ya HAVE to remove it. Could be wrong, tho. Just drain the radiator....that will lower the coolant level enough that you don't make a huge mess. The throttle body also has coolant running thru it, so you will loose some there IF you take the hoses loose. If you remove the throttle body, you'll need the gasket that goes on there, between the TB and the plenum.
You'll need the t-stat, and gasket for it, too, of course. To make it easier to fill the system, and burb the air bubbles, the new t-stat will usually have a small hole in the edge, with a little chunk of metal in it to act as an orifice. Take some side cutter pliers(dikes), and cut that little piece off, so you have JUST the hole in the edge. This will give the coolant a small amount of full-time flow, and keep air from getting trapped.

In this pic, I drilled several 1/8" holes along the edge of the t-stat, but you really only need the one. If the t-stat you get does not have the orificed hole built in, drill at least one 1/8" hole in the edge.....it'll be much easier to fill the system...

Joel,
thanks for getting back.
Should this have been under the cooling forum?
Hope this will help.
Thanks again.
Joe

Naw...it's in the correct forum, since it is a Non-C3 issue. Yer good. 

No, not really. Unless you go down into the 160* range, that is. A t-stat that is rated far lower than OE will allow the stat to open sooner than "normal". It can also sometimes cause a lot more condensation to form inside the engine if the engine is allowed to idle for long periods of time, or if you just start it and let it run, without actually driving it.
These L98 engines were designed to run in the 225*-230* range. Putting a lower rating stat in will not change that....it might just take it longer to get to that temp, but it will eventually get there. The thermostat doesn't control the actual engine temp....it simply control when the coolant starts to flow. The rest of the system components(w pump, radiator, fans, etc) are what controls the actual running temps. Well.....that, and the driver's foot....
180*, or 195* stat is perfectly fine.

Joel,
thanks again for the info!!!!
Joe