True or false ?

[GuzziNZ]

So my 850T motor is down to the last nut and bolt and needs some work.
Camshaft exhaust lobes are toast and matching followers are pitted.
Crank mains measure up within spec but the big end journal seems to be below spec on the "unworn" area according to the Haynes manual.
Also the manual does not give a big end running clearance spec.
I have been told a few contradicting things and would like if someone could clear them up.

Can the crank be ground first undersize without needing nitriding again?
Can used followers with little wear be resurfaced?
And finally what is the min/max clearance for the big end?
Cheers.

[Antietam Classic Cycle]

Can the crank be ground first undersize without needing nitriding again? Yes.
Can used followers with little wear be resurfaced? Yes

[acogoff]

   Be aware that the cam followers are not flat. They should be ground to a 1 meter radius, I believe, so they tend to spin a bit.

[Two Checks]

This tells me based on experience from my T to examine the rocker arm bushings and the rocker shafts.
I forget the clearance between the rocker and shaft. That was 30 years ago but it sure made the valve train  quieter.
The shafts were clogged with timing chain tensioner...and it had a filter!

[Scout63]

Guzziology has a good discussion on grinding cranks if you have a copy. If you don’t it is a very worthwhile purchase.

[GuzziNZ]

Thanks everyone. Yep rocker shaft oil holes were blocked with I guess tensioner block rubber and I have a  old copy of Guzziology so will have a read.
Found big end running clearance in the Haynes manual after all.