454 Running Hot

turbojimmy wrote:

justlou wrote:
Was the replacement engine out of an RV or passenger car? If it was from a passenger car it will not have a camshaft suitable for RV application. An RV camshaft builds torque in a different RPM range than a passenger car application and your engine may be working too hard on the hills causing it to run hot.

I didn't actually see it, but I was told that it came out of a custom-made, antique rollback. It's a GM Performance crate engine. I checked the VIN and it's a truck-spec engine with a 1990 build date. Head stampings come up as truck-spec too. It had an undersized QJet on it so I put a stock-spec, rebuilt QJet on it. Now it has NO problem power-wise. It pulls it along quite nicely. It will pull it up the hills at 55-60 MPH but the fact that it can do it doesn't mean I should push it that hard. Slowing down a bit might allow it to run cooler.

And...at Autozone the only options are 195 and 160 in thermostats. I'm going to go with the 160.

Jim, when I was having overheating problems with mine when I first bought it I found a 180 thermostat that I used for a while, Once I got the overheating issues fixed the lower Tstat caused the eng to throw codes in the fall and winter. Just be aware of that. I thought the older 454's used a 180 Tstat. I think I bought mine from Adv Auto or Napa.