The idea that you need 3.73, 4.10 or an even lower gear ratio is outdated 1970's thinking, from back when a big block V8 had a whopping 175HP and transmissions had 3 gears.
Gearing is gearing. Doesn't matter if it's in the transmission or in the rear end.
Nowadays it's in the transmission. The Chevy 6-speed has a super-low 1st gear to get the load moving. 4.something:1 vs the 2.something:1 in a 4-speed.
The Chevy 6-speed has two extra gears between 1st and "direct" to accelerate the load. In fact, the Chevy 6-speed does not have a "direct" (1:1 ratio) gear in the transmission at all. It has a 1.15:1 4th gear and a .9:1 (IIRC) 5th gear.
The fact of the matter is, the engine with a 6-speed/3.42 combination will be turning RPMs similar to a 4-speed/4.10 combination.