(Crossposed from Expedition Portal): Closing in on 3 years now of using the 2004 Suburban (1500, LT, 5.3, 4x4, 4L60, 3.73 gears) as our primary tow vehicle. Previously we had a 2,000lb [email protected] trailer but in January we upgraded to a ~ 3500lb R-Pod 179. The "issue" I'm having is when climbing steep, high passes (here in CO you can't get from the Front Range cities to the mountains without crossing at least an 11,000' pass.) As I slow down, of course the 4 speed 4L60 drops into a lower gear. 2nd gear is actually pretty good for climbing and I can typically keep up with traffic at around 50 mph even in 2nd. But as the hill gets higher, the weight bogs the rig down and speed drops. When it drops below about 35, the truck wants to kick the transmission down a 1st gear - which of course makes the engine spin around 4500 rpm (screaming.) That typically only lasts a few seconds before it shifts up to 2nd but then it bogs down again and drops back down to 1st. This sometimes happens 5 - 10 times while ascending a steep pass (think Eisenhower Tunnel or Berthoud Pass, for those familiar with them.) When we had the [email protected] this never happened, we could stay in 2nd gear the whole time. But our trailer weight has nearly doubled and I can really feel it when climbing those steep passes. Not only is it a bit of a shock to feel the truck dropping down into 1st gear, I'm worried about what those hard shifts and high RPMs will do to my transmission and engine (transmission was rebuilt 2 years ago @ 150,000 miles and has worked fine since then.) So my question for the GMT800 Hive Mind is this: If my goal is to be able to ascend passes more easily, should I be looking at doing something to boost power/torque or should I be looking at lower gearing? I'm not looking to spend a ton of money and I don't want to put too much stress on an already middle-aged drivetrain (170k) so I don't think turbo/supercharging would be a good idea for me. Are there less "radical" power mods that would boost the power of the engine? EDITED TO ADD: I'm not a huge fan of things like Cold Air Intakes or air box removal - I'm just skeptical that they really improve power. Ditto for "reprogramming" the computer, as I think that assumes that the "tuners" know more about the engine than, you know, the people who BUILT it. Adding power and sacrificing reliability or utility would pretty much defeat the purpose of what I'm trying to do here. Or would it be a better idea to simply change the gearing to, say, 4.11? And if I was to do this, what would I be looking at, cost-wise, to replace the front and rear gear sets (and ideally retaining the G80 locker in the rear?) Anyone else had this issue with a 1500 'Burb towing? (If I'd known we were going to be getting a heavy trailer like this I might have held out for a 2500 but that's 20/20 hindsight at this point.) Thanks in advance!