I am in the process as well on my JM604. Look at post – JM604 Clutch Adjustment -for some pic's. From what I can see they all function in the same way, but some adjustment points/clearances are different. In the manual they should tell you clutch pedal distance adjustments as well.
Thanks for the info. Right now my son has the tractor at his house w/the manuals. I forwarded all to him inc. JM604 info & pics. I'll see if we can match this to our manual. Meanwhile I will accept any other info from the net. Thanks again, Chuck.