Think about what that piston is doing when you do that. It's trying to pick back up and not having a good time of it. Now as an example I'll give you my experience with lugging an engine. Please bear with me as this is an off brand, read Ferd. It was back about 20 years ago I bought a used ranger with a 2.3 liter engine with 110,000 on it. The previous owner got it new and I rode with him couple of times while he owned it. The 4 speed was in top gear buy the time it was at 35 mph. The lugging over a long period of time made those little pistons wobble on the wrist pin and about 20,000 after I bought it one went sideways. It egg shaped the cylinder wall enough that the piston lost the battle.
Now the old 2.3 pistons really have a short skirt on the and are really sussepitable to this lugging effect. The skirt on our old 235/216s are a little longer and probable not as apt to wobble in there bore.
Now in my opinion you should never let your engine work that hard to take off. You probably drive your truck enough to know when it's lugging so going back one more gear, to 1st, would be kinder to your old truck. I believe from experience that a few rpms are your friend, not your enemy.Larry
