Does the engine have to be on TDC to just take off the valve cover and swap out both intake and exhuast rockers and shafts?? I wouldn't think so, but need to know for sure before I do the job.

 

no but makes it easier is all, esp if you rotate the engine to where both valves are closed when you do each r&r But I'd def measure the shafts with a micrometer or have someone that knows how do it for ya to make sure they are the correct length before just sticking them in with 100% trust