If your truck has 30 inch tall rear tires, the 4.11 rear gear will give about 2750 RPM at 60 mph.The governed speed on 216's in bigger trucks was 2800-3200 rpm depending on the application.So if your 216 is in good shape,spinning it to 55 mph for like say an hour shoulbe be within design limits.
Some will say the engine won't last,I used to drive a 51 Chevy dump with a 216 wide open against the governor for a few hours at a time, day after day.Oh, it got to knockin after a time, but took about 4 months of torture to ruin the bearings.
Try it and see what happens,if she blows,I don't know nuthin
