I did it with the batch 2 and got very good results.
if you have the older gear batch 2 to 7 with 162 chips
set fans at 60% which is about 4200rpm . the fans max at 4600 rpm and about 75% setting but my gear did better at the 60% setting.
as long as temps are 62 c and errors are under 0.0010% you are good to go.
I don't own any match 8-13 gear with 145 chips
IMO older batches should work well at 12.8V and 700MHz reaching 5.67Ths - chip heatsinks are same dimensions older and newer batch, so OCing older batches to 700MHz must be safe and still better GH/W ratio than older batches