Hello chevroletforum. I have a 1989 Chevy Silverado single cab short box 4x4 K1500 with a 350. I had to replace my radiator about a year ago. When I got it home from Napa I realized it was bigger then the stock one, but as I was in a hurry and had had overheating issues with the old radiator over the years, I installed the new larger one without too much trouble. I believe it was actually meant for a 2500. I've heard engines don't run efficiently when they are too cold. During summer months the truck now runs at normal temp but this time of year the temp gauge hardly moves. I plan to put a higher temp thermostat in to try to raise engine temp closer to normal, as well as testing the temp sensor and temp sending unit. My question is, is this a waste of time? Are the radiators too different for my truck to run how it should? Will emissions be too high to pass smog? I will say I don't notice much change in performance or mpg. Any insight would be greatly appreciated

 

I wouldn't think its the radiator. It's usually better to run a larger radiator on those older trucks in my experience. Of course I live close to Houston where we tend to be 80 degrees on Christmas day, so being to cool is only an issue for about two weeks in Jan or Feb.

 

I agree that a larger capacity is not going to have any adverse impact to engine performance, but the thermostat very much will... if you have the correct OEM rated thermostat installed you should be fine.

 

Thanks for your replies. That's what I was hoping to hear. I put an OEM thermostat in her today so hopefully things balance out. And yes, the one I removed was stuck open. Thanks again