2.66 low gear vs close ratio

Well I'm back, so let's play with applications,starting with the O/D boxes.
The ratios are 3.09-1.67-1.0-(.71/.73) and the splits are .54-.60-.71/.73 hereafter .71

-Say you have a slanty that rarely sees 4000rpm.If you put this box behind it, and want to cruise at 2000/60mph, then you will need 3.73 gear.This will get you a nice 11.53 starter gear, and a 2.68FD (Final Drive).So that's a double win so far.Next let's work the splits; Let's use .575 as an average % drop. Shifting into 2nd from 4000/1st, the Rs will drop TO 57.5% of 4000, so to 2300. the powerband will thus need to be from 2300 to 4000 equals 1700rpm. This is very doable in this application
-Now let's put this same stuff behind a stockish teener.This baby might want to be shifted at 5000. So the rpm drops to 5000 x .575 = 2875; and the power band is thus from 2875 to 5000 =2125rpm, still doable.
-Next, let's put this behind a 360 that want's to be shifted at 6000. the rpm will drop to 6000 x .575 = 3450;and the powerband will need to be from 3450 to 6000 = 2550. This is getting tougher. This combo will need a cam that provides a long power curve, which usually means some sacrifice in specific output. So now begins the compromising. It will still work on the street cuz it has 360cubes and 3.73s out back. But it will lose it's fun factor with each gear-change. And it will not do well at the track.
-Finally let's put it behind a hot 360 that want's to be shifted at 7000. the Rpm drop will be 7000 x .575 = to 4025. And the power band will need to be from 4025 to 7000 = about 3000Rpm. This is unrealistic for performance. Of course you can still drive it on the street, for the same reasons as the last combo, but it will be kindof a slug compared to what it could be with a tighter tranny gearset. And forget about racing it; The cam is impossibly large for these ratios.

-So you see what I did here; starting with a low rpm engine and working up in 1000rpm steps, and showing how this tranny works with different engines and applications, all the while keeping the starter gear constant at 11.53. This is an excellent all-round starter gear for all Sbms and the slanty does ok with it as well.It is the same starter gear as 11.53/2.66 = 4.30s with the standard 2.66low box
Typically 4.30s are the go-to gear for running from 115 to 125mph with a SBMs. However,with this box you have to get there with just 3 gears,so you better have some serious power.
Long story short is this; this ratio loses it's appeal with engines that need to really wind up.It works best with low rpm engines like slantys and stockish teeners.
So let's move on.