Just installed gauges. Climbing up mountain (to Big Bear) under WOT, truck empty (not hauling anything), and gauges read 1,400 degrees! Using Hypertech on Stage 3. Cruising at normal speed up hill temp reading between 900-1200 degrees. Temps seem awfully high to me. Worried about what will happen when I'm hauling 14,000 lb. 5th wheel trailer. Plan on going down to Stage 2 when towing. Will let you know what happens...
P.S. Exhaust is stock. How much of a difference will bigger exhaust and with/without CAT make?

Exhaust will lower your EGT's several hundred degrees. You will see a difference. Some will say don't go above 1400 but many will take the truck there and beyond, just don't keep it there for long. I have pegged my 1600 gauge several times, I just don't stay there for too long, maybe a few seconds at the most... Good luck

1400 is the rule of thumb, I wouldn't keep it any hotter any longer than you have to. Heat is the enemy of lifespan.

The reason there is a temperature limit, is because the pistons are weakest link in the chain. The stock pistons are aluminum, and begins to deteriorate (at a molecular level) at about 1450F. Temps above this will compromise the overall lifespan of the pistons/rings.

Keeping the temps below 1350/1400 (PRE-turbo) will make sure you don't do any damage to engine parts, and get the maximum useable life from the components.

EGT's are probably the most critical temp you can monitor.

My 2 cents.

GMC2500HD,
I know working with pressure gauges that if you peg them out you stand a good chance of tweeking the calibration on the gauge. In other words if you peg it out and the actuall reading is about 200 higher you may be seeing 200 lower than the actaul reading should be.
I am not sure if this is also the case on the EGT gauges or not, but I don't see how it would be any different.
Somthing to think about.

I will take that into consideration but it still seems to be working properly. If I suspect at any time that it is not working right then I will pull it and send it back. Not an issue there... Thanks

An EGT gauge is based on a known electro chemical reaction at the pyrometer tips.
It will hold it's calibration as well as an Ohm/Volt meter will. How do I know? I have an ohm/volt meter that doubles as a pyrometer.

Thanks for clarrifing.

Aluminum alloys will melt at 1250F
The best High Silicon content alloys 1400F
All will show signs of spalling and stress cracks at sustained temps of 1300F
Metallurgical websites list almost all grades of AL and what their charecteristics are.

The Hypertech programmers are known to have very high EGT, my opinion is they rushed to market with a poorly tuned product.
Superchips tuners make the same power but with 200 degrees less EGT.
You can't remove the Cat, 1) it is illeagal, 2) it will set EGR codes 401 and 404.
A Banks high flow exhaust from the cat back combined with an AFE Stage 2 cold air kit will lower EGT considerably.

My EGT's hit the 1350 mark with the EDGE set on 0 (attitude max EGT setting is 1350) when I hit the peddle hard. This is when it is unloaded on a flat surface. I ran 65mph to work this morning (it was 52deg outside) on level 3 and the EGT's ran about 550 deg to 650 deg depending on flat surface or climbing a slight grade.

Where you in TH mode? That will lower the temps.

I run the Htech level 3 with 315's up highway 38 to big bear 2 weeks ago and didn't have any issues, whether in TH or OD. A couple times I hit 1100 but never anything over that. Also your 900-1200 hill temps seem high for average hill climb.

I do not have a cat and I have a lb7, which I understand runs cooler than the lly.

radvans:
Tried both TH on and off, but it did not affect temps. Going to detune Htech and see how how it runs then. Going to make a run to Glamis with trailer in a few weeks. Will try different tunes and see how temps go. Thanks for input.

Traveling on flat level ground (I-80 in central Nebraska), with no wind (unusual in Nebraska), towing our 5th wheel with a combined weight (truck and 5th wheel) of 15140 lbs, at a steady 60 mph, boost was 4 psi & EGT was 800. At a steady 65 mph, boost was 5.0 psi & EGT was 850. At a steady 70 mph, boost was 7.0 psi & EGT was 875. At a steady 75 mph, boost was 9.5 psi & EGT was 900. Juice set on level 2.

took out program tonight (stock). up hill WOT still saw 1200 deg. egts. in case it matters installed porob in exaust manifold per hoot method