GMC - DANA 44 - which gears to buy?- I wanna burnout!!

[kieth]

Originally Posted by boucher racing

The gears are from the factory, 3.54

Kieth, first of all thanks for the spreadsheet. It is really useful. To answer your concern. I used your spreadsheet and came up with this.

I am comparing the new set up with my old setup (T5). With the 3.54 / T5 setup, I was turning 2300 rpm at 70 mph. With the 700R4 and 4.11 gears, I will turn 2300 rpm at 69 mph, so it is very close. I did like the highway setup with the T5, nice power on tap at 70 mph. It did not lug, it seemed to be at a sweet spot.

Also, look at the power ratio off the line (1st gear X rear ratio)

T5 - 3.76 x 3.54 = 13.3
700R- 3.06 x 3.54 = 10.8
700R with 4.11's- 3.06 x 4.11 = 12.6

The T5 in first launched really hard. Now looking at the 10.8 number, it sort of explains why it feels weak. The 4.11 gears get the power ratio close to that of the T5.

So... I am pricing a set of "thick" cut 4.11 and install.

We shall see!

Boucher'

Great information, I did not realize the t5 was that low in 1st gear. One thing though, if you put your foot on the brake with the 700r4 you not only have the gearing of the 700r4 but the sharp rise in torque available with the torque converter.....that means more torque available and I bet she will smoke em with a heavy foot..........have fun Kieth