sounds like your ujoint needs replacing. grab the axle shaft and give it a shake. The Plus Sign shaped item inside should feel nice and tight with no wiggles.
and he can still do that. only he is in his shoes. I'm just saying that doing an engine swap every couple years sound very tiring to me. But then on some days, walking out for the mail sounds tiring to me so everything is relative
but what's the health? we've got a few members with over 300k on the original engine. If the engine is pretty healthy, then it would seem to me that you can skip a huge amount of effort by leaving it alone until you're ready for the v8.
are you talking about just swapping the engine itself and keeping your current wiring/injection?
also be sure to add in your truck's specs to your signature