68 289 4 bbl, started up, ran fine then noticed some smoke from the right tail pipe. Pulled the plugs andfound the 4 cylinder plug was black. When I took of the right side valve cover found that the Intake vavle (4th cylinder) rocker was broken in three pieces. OK, so I have to replace the rocker. But, will this eliminate the smoke or is there now another issue, leaking valave stem seal?

Thanks,

 

I would say "yes" to the question of eliminating the smoke. However, this happenned to me once and the reason for the push rod, valve/rocker assembly failure was due to faulty machine shop work on a previous head rebuild. I would suspect that the stud used to mount the rocker assembly is backing out of the head. Make sure you check the dimensions beofre you just replace the failed components.