constant ticking

I have an 82 F250 and the damn thing won't stop tickin. When I'm idleing, accelerating, or driving, it always ticks. As the RPM's increase, so does the speed of the ticking, I originally thought it might have been a lifter jammed or clogged or something. Tried putting STP in it the other day but the ticking continues. I just changed the oil about 500 miles ago so I know it's got plenty. Any ideas?

You need to replace your speedometer cable.

stp wont free up a lifter, sea foam might help but you may have to tear into it, find a nice mechanic and have him listen to it with his stethascope, that'll tell you for sure but i'd say lifter too

Could it be an exhaust manifold gasket?

Could it be an exhaust manifold gasket?

didnt think of that, very well could be an exhaust gasket of some kind