Easy (?) OD Auto Install

If you liked that, then here's one more;
the A999LU with 2.94s, and a 3200TC and keep the small tires.
It looks like this;
70=2770 in LU..That is a drop of 730 rpm or 20.8%. this is equal to an overdrive gear of .79, and all other things remaining as in the current combo.
Your starter gear is only 2.94 x2.74=8.06 but with the 3200, and the same 180/300ftlbs input, this maths to a possible 4180ftlbs at zero mph and [email protected] ratio.
This compares favorably to the 4210 of the current combo, so as good as no loss of take off at zero mph. however; 60mph in second is now maybe 4400...... which could be a GREAT passing gear. but not the best place to trap 60 with, unless the cam is a stocker.

If you wanna play the numbers, here are the formulas;
For cruise rpm;
mph=(rpm x Tc)/(1056 x R1 x R2);
this is for Zero slip; add 5 to 8% for TC slip, if NOT a LU. And
Tc is tire circumference, AKA roll-out, which is diameter x 3.1416aka pi,
and R1, R2 are the gear ratios; trans and rear.
Also,
to figure the torque to the road;
crank torque times ,all the gear ratios, times the TC ratio, and corrected to a 1ft radius so I can play with tire sizes. Lessee that would look like;
ET x TCr x R1 x R2 x (24/Tc); where
ET is Engine-Torque, TCr is Torque-convertor ratio,
R1/R2 are the gears, and Tc is installed tirecircumference
The TCr, at WOT, varies from about 1.8 at zero-mph to something like 1.1 at the top of the track. It is constantly changing with torque input and load. So it is greatest at zero-mph, until the tires slip, and diminishing with rpm and speed.
So, I used 1.8 for all your calculations, just to gross up the numbers for effect,lol. The number you need to think about, if you want to spin the tires, is about 3000. It doesn't take that much to break them loose, but it will take that much to keep them spinning when the TCratio starts diminishing. Unless you just whack it up to peak horsepower and hold her there,lol, which is a lottta fun too.