[66 C10 383]

I went to that site and it wouldn't let me open it due to not being a member.

We spoke of this previously in the past but I couldn't understand what everything meant ... numbers aren't really my forte' ... LoL

Can you help me understand it?

I plan on running a 28" tire (275/60/15) with an aftermarket T56, my tranny gear ratios are

(1st) 2.97
(2nd) 2.07
(3rd) 1.43
(4th) 1.00
(5th) 0.80
(6th) 0.62

I can't decide on using a 3.73, 4.11, or 4.56 rear gear. The cam I have (hyd roller) is a 230*/236* duration @ .050" lift. & has a usable range of 2000-6000 rpm. I was advised to have my highway rpm about 2100-2300 rpm. I will be running multi port fuel injection (TPI based setup). "Estimated" power will be in the 450-500 range on both horsepower and torque.

Most of my driving (to work ... ) is at 55-60 mph right now but if I move (very likely) my drive will be interstate driving at 70-75 mph.

Here's what I've come up with on my own but I'm not sure what to run rpm wise for the best mpg's.

3.73 x .62 = 2.31 final gear ratio
55 = 1525
60 = 1663
65 = 1802
70 = 1940

4.11 x .62 = 2.55 final gear ratio
55 = 1683
60 = 1836
65 = 1989
70 = 2142

4.56 x .62 = 2.83 final gear ratio
55 = 1868
60 = 2038
65 = 2207
70 = 2377

3.73's seem too low based on my rpm recommendations, 4.11's may even be a bit too low, the 4.56's seem about right ... based on mph's and rpm's ... ???