I'd like to preface this by saying that I don't have recent first-hand experience here -- this question stems from "complaints" from my wife. We have a 1999 Suburban with the Vortec 7400 big block. This is a 3/4 ton truck, towing capacity is 10k lbs and it has transmission cooler, power steering cooler, etc. It's our tow vehicle for a 2 horse trailer -- it's got plenty of capacity for what we're towing. I'm think it's got a 4.10 rear for the benefit of towing too. We live near a pretty big hill, about 3 miles of 7% grade, and she's gotta tow up that hill in order to get to one spot she goes riding. She feels like the truck doesn't have enough power. Now, I'm sure it is a little worn out given it has almost 170k miles on it (we've only had it for a few years and 10k miles or so though) but I think it just sounds like it's working because of the low gearing, 4 speed transmission, and lack of sound deadening. Given the 4 speed, there aren't that many choices if you want to move at freeway speed. Not a problem on the flat, but on the grade this can be annoying. She doesn't want to drive up at 35 mph if it can be avoided. I told her if it doesn't want to pull in 3rd gear, just to drop it 2nd and drive up at 50-55 mph at 3500 RPM. But then, I'm used to cars with small, revvy engines. Is this appropriate treatment for a big block or should I just tell her to take it easier and go up at whatever speed 3rd gear will allow? There's no redline marked on the tach but under heavy throttle it will shift at around 5000 RPM IIRC. Torque peak is around 3200 RPM.