n14 inj rocker arm moving to fast

[RocketScott]

I guess it's possible to do it in frame but it would be a nightmare

Front cover has to come off, the front engine support bolts in front of it so you'd need to support the engine without it. Trans has to be pulled back to take out the clutch and flywheel. Then the rear cover

Sounds like there is more to your problem than swapping a crank will fix though. bwake is spot on. The whole thing needs to be gone through

Just drove the mechanical N14 I rebuilt back from the shop today. It's not a fun process to work on these old engines. Hit me up if you need anything, I bought a timing jig and the boring tool for oil pump bushings just for that engine