Since I had a shop do the clutch ,I don't know if the flywheel was resurfaced but since they only work on Datsun and Nissan , I assume they would do it right. I've done a lot of clutch jobs where the flywheel just needed to be deglazed. I took another look at the timing and it was jumping back and forth at least 5 degrees. I changed the rotor and it was steady. When I got the car it wasn't jerky But one of the first things I did was replace the distributor and the car sat in my garage for 5 years.I replaced everything I could to prepare for future unavailability of parts. Nothing was actually bad. Maybe the rotor was the problem. The new one was a little different. I will take it for a drive to see what happens.