That 5.3 will happily spin 5500 RPM all the way up ANY paved grade you can find, in first gear if need be. It won't hurt it a bit. If it bothers you, trade it for a diesel. Because torque peak is up at 4000 RPM, and trying to keep the revs down isn't gonna help.
'06 GMC C2500HD RCLB gasser 4.10:1, 4L80E, custom camshaft
'84 Trans Am 6.2 diesel, 700R-4, custom Class-3 receiver
'69 F350 dually. GM 6.2 diesel, turbo, 700R-4, NP208 all pending.
For the sake of the engine and transmission when in the hills keep your RPM at 3,000 or greater and never use OD but if you observe the 3,000 RPM rule you are not going to be in OD when towing in the hills anyway.
Going down No OD either and you will need to be in 1 or 2 in some cases going down steep grades inside of parks, etc. That is a good engine but you may have the lighter 4L60 family of transmissions.
whisperide wrote: That 5.3 will happily spin 5500 RPM all the way up ANY paved grade you can find, in first gear if need be. It won't hurt it a bit. If it bothers you, trade it for a diesel. Because torque peak is up at 4000 RPM, and trying to keep the revs down isn't gonna help.
The 5.3 is not a tow monster in any sense of the word, but like the 5.4 Ford, if you push the pedal hard enough and long enough, it will get to the top of the hill. I can't imagine any highway grade that could not be climbed at 4,000- 5,000 rpm in whatever gear is necessary to keep the rpm's up. "If" your plan is to only climb mountains, then there are better options.
This is a timely thread for me! Thanks for all the input. I've got the same setup, except an '03 4.8liter, pulling a 3000lb dry weight. Same engine, detuned. I have historically had a very light foot. The truck may go years at a time not going over 2500rpm. Just bought the "brick" a few weeks ago and the truck is probably wondering what the h_ll happened. Almost all my towing is in pretty good foothills, and 20% of it will be the Appalacian Mtns.
This last trip, all but a few hills were climbed at 2500rpm, and two or three required another downshift and 3500rpm. I was on edge the whole time. Sounds like I just need to relax and let it do its job. I'm highly conscious of fuel economy, and just hear the bills being ripped from my wallet when up at 3500rpm. Maybe that's not the case? Hope I can adjust my perception.
I've got 80k on it now and have never had a tuneup. I'll change out the plugs soon. Need to change out the drive belt too.
Turn off overdrive. Your truck cannot maintain 2000rpm at 65mph pulling a high walled RV. Use 3rd gear, right around 2500rpm at 65mph. Speed up downhill and slow down uphill. Keep the torque converter locked at much as possible. Enjoy.
A & A parents of DD 2005, DS1 2007, DS2 2009 2011 Suburban 2500 6.0L 3.73 pulling 2011 Heartland North Trail 28BRS 2012 VW Passat TDI
Had the same truck as you have only I had the 3.42 gears. Pulled around 6-7K for a few years then went to the 6.0. The 5.3 sounds like it running the way it should. Mine with hit 4K on any small hill it looked at. I never ran the cruise control while pulling the truck, if I did then it would hit second gear very quickly at times. If you need to change gears sooner do it manually or drop the pedal on the right a little harder. Sometimes mine would lag in 3rd and I would drop it to second manully to get the boost needed for over the hill. You will have no problems with that engine, the only drawback is the tranny. You need to leave it in 3rd with tow haul. This also puts the engine in its sweet spot and pulling should be more enjoyable. I run K&N filters in all my vehicles and have had no issues with that product. Dont go buy the exhaust deal...just makes the truck louder when towing.
Let me just verify everything. I'm reading get the truck out of O/D. The truck is in D with the tow/haul button pressed. I'm a bit confused when I read turn off overdrive. Is the tow/haul considered overdrive?
A few have said put it in 3rd. That would mean to move in to third on the steering wheel column, correct? I'm thinking that would automatically move the rpms higher which is what is needed to obtain more pulling power/torque.
By the way, I calculated mpg at around 9 this last trip.
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Almost all my towing is in pretty good foothills, and 20% of it will be the Appalacian Mtns. 
