I’ve written here and there in these pages and elsewhere of my strong preference for ratchets with a high tooth count—at least 72 or 80 (some have even gone beyond that).
The advantage to this is the ratchet handle does not have to pivot as far to engage the next tooth (or teeth, as most ratchets engage multiple teeth). And that is a significant advantage when working in tight spots where you do not have much room to swing the handle. An 80-tooth ratchet needs just 4.5 degrees of movement to advance the socket, whereas, say a 48-tooth ratchet would need 7.5 degrees. It might not sound like much, but sometimes it means the difference between very limited access and none at all.
I had another demonstration of this advantage the other day, when I had to replace the clutch master cylinder on the FJ40. For some reason the cylinder I bought interfered just barely with the brake master cylinder’s booster, so I had to loosen the latter from inside the footwell. And the upper left bolt of the bracket sits just so between a reinforcing strut and the brake pedal, so that swing room for my ratchet was reduced to . . . well, just abut 4.5 degrees. However, that was no problem for the 80-tooth 3/8ths ratchet I had on hand.
You might think that the strength of the ratchet head would suffer with such a fine engagement, but in fact modern ratchets are probably stronger than older, coarser models due to better metalurgy and that multi-tooth engagement. One of my favorite tool investments is a Snap-on SX80-A flex-head 1/2-inch ratchet, with an 80-tooth head and an 18-inch handle—the same length as a common, non-ratcheting breaker bar used for loosening the tightest large nuts on transmissions and suspensions. And that’s how I use this, knowing that Snap-on makes the same ratchet with a 24-inch handle. Obviously they have confidence in that head.