How many of us are there? Owners of Dodge based RV's?

Thanks Griff, that would explain the coaxing the engine to higher speeds until it smooth's out. I had a 340 do that to me once. (same basic block as a 360)
Once the chain gets loose, I've seen all kinds of erratic behavior as described. Once it's loose enough to jump, it can go any which way if you keep driving it.
Anyway, just my two cents.