Cordless, 4" angle grinderWhat tool did you use to cut out your hood?
Cordless, 4" angle grinderWhat tool did you use to cut out your hood?
I also should have used a drill in the corners first but I forgot.
Yeah, a person could do better than me. If a fella put a piece of sheet metal between the hood brace and the skin, it would be a lot easier to avoid cutting through the brace at all....and a surgeon’s touch.
David
I'd redo the shroud and fan mounting to match the full size of the radiator before messing with tuning. It's an airflow issue for sure.
I have the CTS reading on the Holley and the Autometer gauge. The senders for both are located at the front of the intake before the thermostat. Technically the Autometer was giving me a higher reading once the motor got over 200F. So when I'm saying I would stop at 220F to cool off that was what the EFI told me and the Autometer was usually reading closer to 230F.Also just another thing to think about which I bet you've already done, check the gauge accuracy. Does the gauge match your ECM?
The heat exchanger for the tranny in the rad is awesome if you can utilize it. There's always the possibility it was the straw that broke the camels back but I doubt it. A 7.4 and 80e is a factory combination so you should have lots of breathing room if its built similar to factory.
BTW you should have a richened mixture under certain higher TPS conditions and loads. This will have an effect. I would bet the Sniper does it but check to see if power enrichment is enabled.
Same with timing tables. That will definitely add different heat conditions. Is it retarding timing at all due to knock etc..?
Having a positive pressure zone in front of the rad like @AgDieseler said will definitely help, but not on the trail.

So right now it just runs on the base tuning as well as the learned tuning the onboard software does for the first however many miles of driving.I was curious what you were running for a fan on the 8.1L. I don't know if you remember the climb up 285 from 470, but it's pretty tough. Too bad you don't still live here so we could do a direct comparison. Obviously I was being passed by newer trucks pulling bigger campers as I sat on the side of the road cooling off, so it's not an issue for the newer trucks. The camper weighs about 4000lbs, so I try to remind myself between truck and camper and family and gear I'm probably hauling nearly 13,000lbs. Maybe I'm expecting too much from a factory 80's truck 454. I also had to pull Nick's truck up Kenosha Pass and it was heating up pretty quick doing that but it's a relatively short climb.What radiator/size radiator are you running now? I swapped in a 6.2 radiator and shroud from a square body truck into my CCLB, and only have a mechanical fan on the 8.1 (no e-fans at all), and last weekend when we went camping, it was a long 2-lane mountain road that was probably a 4% grade for about 15 miles (with the camper in the back with all our crap in it...so maybe not quite as heavy as you towing your trailer, but not that far off either) and my temps never got above ~185* the whole time
I think that will be the next step. I'm deciding between 2 options. Factory 6.2L mechanical fan (uses same fan clutch as 454) and shroud. I found I can get a 6.2L shroud from Classic Industries. My only concern is trail cooling. I was just reading @the_blaze thread and he's having idle cooling issues with the same mechanical fan and shroud.I agree with the thought that you are not maximizing airflow through the radiator.
I know my setup is an apples to oranges comparison, but follow me here. Using a 6.2 radiator, stock shroud for that radiator and a stock 5.3 fan and clutch I'm over cooling. I believe it comes down to every ounce of air comes through that radiator goes out the back of the shroud.
Gm sealed all the fan shouds up that way for a reason. Leaving gaps to allow for air forced at road speed is leaving some of the cooling capacity off the table. It hurts even more when the speed drops due to load or trail and the only airflow through the radiator is what the two fans are pulling.
I'd redo the shroud and fan mounting to match the full size of the radiator before messing with tuning. It's an airflow issue for sure.