[87Skier]

Just a few weeks ago I ended up towing my Jimmy. Ended up around 6,100 lbs loaded behind a 96 K1500 Suburban (350 with 4L60E). Unfortunately, it happened to be about 103 F that day, 260 miles round trip with a 5000' mountain pass in the middle.

This was not a fun trip. My Suburban did it, but it's really pushing it. At one point, I pulled onto the highway at an uphill section. Even at wide open throttle it took about 30 seconds to get to 30 mph. Every time I accelerated to 60 from a stop the engine would heat up 20-30 F even doing it very slowly. When I climbed the pass, I shifted into 2nd and ended up doing 30 mph for most of it. Kept the engine temp under 220 F and even ran with the windows down and heat on. I passed several vehicles broke down on the side of the road, hood open. When loaded I never used OD. I didn't want to take the chance, and I would rather do a few more RPMs than lugging the engine constantly.

It's not always about your truck but how you use it. Treat your transmission nice. Keep it cool, don't have a lead foot and it should be fine.

If I had a choice, I would tow with the 4L80E. The gear spacing is better. The 1-2 shift in the 4L60 is 3.06 to 1.62, the 1-2 in the 4L80 is 2.48 to 1.48. The 4L60 drops you too far outside the power band. All the gears are closer and the overdrive isn't so deep in the 4L80E.