25THRSS

Went to the dealership yesterday to get a thermostat and some other stuff for my 92 rs with a 305 tbi and the guy said there were 2 different size thermostats and I had no idea which one to get. I was really suprised because I thought all sbc's had the same thermostat. What gives and which one is the right one for me?

Zap Racing

Read Willie's article above!!!

25THRSS

I have read the article and it mentions nothing about my problem. All I wanted was a stock 195 degree thermostat for my 1992 camaro rs with a 305 tbi. I was under the impression that all small blocks had the same size thermostat, but the guy at the parts counter told me otherwise. I even gave him my engine code, which is E, and he still asked me which one I needed, as to which I had no idea so I just left without getting what I needed. Are there different size thermostats for my car or is the guy blowing smoke up my ***? Maybe he thought I had a v6 or something, I dunno?

Zap Racing

What were the choices He gave you?

flyway190

Can't you just get both and take back the one you don't need?

25THRSS

I think he said one was 52 mm and the other was 58 mm in diameter. He might have said 42 and 48, but I think it was 52 and 58 mm.

flyway190

The last one i pulled out is closer to 53 mm in diameter.

Zap Racing

Learn something new every day!

25THRSS

Yeah, tell me about it. I haven't heard anyone ever talk about there being more than 1 thermostat for my car. I wonder if there is anyone else out there who knows anything about this? When I ordered my hypertech thermostat and fan switch they only listed 1 thermostat and that was for all 82-92 305s and 350s. Weird.

Zap Racing

I think the parts guy was just messing with your head! Ther may indeed be 2 sizes, but the normal physical size is pretty much standard. In all my years in racing stocks and sprint cars, I was not aware of a different"size" t stat!

Can anyone shed some light on this?

Barry85Iroc

I have heard a nasty rumor that there are different physical size thermostats, but I've never seen it. Even the reverse flow is, I believe , the same size. Some of the thermostats have a rubber seal around the rim to help with sealing. Maybe that's what they're referring to..............

25THRSS

The parts guy also said that the 305 tpi and the 350 tpi both use the same thermostat and there is only one to use, but the 305 tbi has 2 available. Weird. I guess I'll find out what's up when I finally take the old one out and bring it to the parts guy so he can just match it the right one i need. What size do the tpi and LG4 cars use?

WS6 Berlinetta

54mm is the size I use for my carbed 350, 307, 305 and tbi 305 in my cars. As far as I know thats the only size SBCs use.

R