[tccrab]

The early "Black Tag" ZF6's are noisy, it's because of the straight cut gears as mentioned earlier by Paul.
My original Black Tag ZF6 in my '90 used to almost sound like a turbo charger in first and second gear at WOT.
I wound up replacing it at the early age of 10k miles because of 2nd and 3rd gear synchro problems. Seems the previous owner or someone in his employ liked to practice their speed shifting and wasn't as good as they thought they were.
The very first time I tried to speed shift at WOT into second I heard the most terrible grinding you can imagine.
I actually found a '95 Blue Tag ZF6 for cheaper than it would have cost to box up my '90 Black Tag and ship it to the ZF Doc for repairs.
The Blue Tag ZF6 is much quieter than the old Black Tag. Hardly any gear noise at all.
My advice is to wind up the car in first gear to say 7500rpms and slip it into second and side-step the clutch.
If it don't grind, you are good to go.
;-)

'Crabs