If it is a modern VR, exciter voltage type, I think the weak link is the alternator itself (windings and diode board especially). The Zeppster will chime in here no doubt.
You don't want a shunt type VR in there.
Upgrade the alt output to keep those 2,000 CCAs in their homey abode.
Heb Dduw, heb ddim; Duw a digon
I'm that gun-totin', farm-raised, evangelical, pro-environment, OHV ridin'/drivin', Southern civil rights pro-labor Liberal yo' momma told you couldn't possibly exist.