90 F350 5.8L 5spd clutch r n r

Your clutch actuation is hydraulic and these systems have only a finite "throw.... If you have the flywheel machined, you should purchase and install a shim to return the clutch pressure plate and release bearing to the correct geometry. These flywheel shims are available at most auto parts stores.

FWIW, I have seen where machining the flywheel doesn't seem to affect clutch operation.... I have also seen where it does.... probably about 60/40 with the big percent having troubles..... The shims are a bit spendy for what you get, in my experience. For my part, I wont install a machined flywheel without one - I refuse to remove everything twice for free... and the customer doesn't like paying for stuff to be removed even the first time....

Sidebar... I applaud you and your mechanical aptitude.. trying to keep older units on the road can be a problem (I have often been called upon to perform $1500 (as a number) worth of work to a unit that wont be worth much more than that when it's done...). However, I see too many that lack this aptitude that can create more cost than they save.... it is important to realize our limitations. "its the only way to go..." isn't a real good statement in too many concerns....