I mounted a large cooler built for Allison transmissions under the cab and plumbed to the trans cooler circuit. I do not tow far very often but when I do weights are 21000 to 23500 GVW. The cooler has a temp switch and fan but I do not know if the fan has ever engaged. trans temps are definitely controlled 200 to 210 max per GMs gage even out west in 103-109 degrees and strong headwind last summer. The engine temp is better but still climbs on pulls in real hot and steep grades, but lasts longer before the heat is too high. The biggest factor slowing the truck is usually EGT climbing toward 1400 degrees. When 1350 is reached I back out depending on the length of hill and ambient temp and load. Overall the trans cooler was well worth the $$.
Opened up the air intake to the filter box and from the filter to the turbo. Changed out the turbo mouth piece for an LBZ mouth piece. this added a slight bit more noise and the turbo whistle is slightly more evident. Blocked off hot engine air into air intake. I believe more air is being pulled because the air restriction indicator on a clean filter is now always set near half way. Worth the $$.
The cat falling off the exhaust system was a very good thing. Overall last 30000 miles a plus .2 to .3 MPG. Slightly more noise through 4" system with 4" see through muffler, sounds good!
I do also run and Edge w/Attitude, levels 1 or 2 only, boost stick, EGR blocked and FingerStick. Oil changes 7-9000 miles that oil analysis show as ok. Trans oil changed every 25000.
Bob O.
2004 K2500 DA LLY CC LT LB Wow! Edge w/A + BS + CAT pre fuel filter, 06 air box,
2002 C6500 EC. 7.2 Cat NoMar rollback/ 92 C7500, 7.2 Cat, 25ton No-Mar / 2005 C5500 D/A rollback / 1969 Corvette 350-350 4spd AC T-top stock orginal
XP850LE WOW nice ATV, 09-550XP hers, 03-Predator, 04 Honda400EX, 05-Banshee, 08-KTM525, 08 KFX700, 38' enclosed GN hitch