For those who have some money to spend, I would recommend that you get the close gears.
However, for those who are on a budget, I would recommend the 4.9 for the most torque multiplication for the rather torqueless 16B.
Moreover, either close gear set OR final drive OR both together benefits from a lightweight flywheel. In this case, the lighter the better.
I'm not sure how many of you are comfortable fiddling around with transmission cases, but it's a good idea to endure a bit of bank breaking to get "all" the other associated parts replaced at the same time.
When doing a final drive/close gear set, we recommend changing the diff carrier bearings, the input shaft bearing, the pilot bearing, the throw out bearing, the flywheel and clutch.
If you want the full meal deal, then consider replacing any questionable looking syncros/hubs along with the factory helical LSD with a clutch pack unit.
It really really sucks to put everything back together to find out the clutch is slipping or there's some strange noise inside the case!