Manual Transmission Advice.

me too! I agree and highly recommend it.
I didn't need it when my engine had the Hughes 223/230/110 cam. With 3.55s the starter gear was only 9.44, but that engine had a ton of cylinder pressure, so it was fine.
but boy-O-boy; just on size bigger cam,(230/237/110) and that 9.44 didn't do well any more; mostly because the minimum driving speed was now about 5.5 mph, and She was no longer a dump it and drive deal. The 3.09 cured that so I could keep the 3.23s.Then with a lil more tuning, I got her down to 4mph.
The starter is now 10.97, just about like the 2.66x 4.11 was. The 10.97starter, I have found, with all three cams (including the 292/292/108) is a pretty nice starter gear. And the 62% 1-2 split is actually very doable.

I did not know that 3.09/direct box came in the 74/75s