Joe, pick up or borrow an older Ford shop manual (it really doesn't matter what year, some time from the mid 60's to the thru the 70's and it should explain about checking the pre-load prior to and after replacing the pinion seal without replacing the crush sleeve.

Another method is to mark the nut and pinion shaft prior to disassembly and count the number of turn to take the nut off. When you reassemble tighten just a touch past the mark.

I’ve replaced a lot of pinion seals over the years on rear ends with crush sleeves and only screwed up one of them......you can tell before you even try to drive it if you got it too tight.

If you’re not comfortable doing it yourself, find a good shop (a local garage or rear end shop who still have some old timers working there) and have them do it.