I swapped 3.07:1 gears to 3.73:1 gears in my '77 C10, and noticed a slight increase in fuel economy (reduction in fuel consumption). Probably due to 1) the cam is now working, and 2) the torque converter (2500 stall) is no longer slipping.
275/60R15's have me close to 3000rpm at 60mph in 1:1 gear.
The_Jed wrote:oldeskewltoy wrote:From what I can gather, the wheels and tires he drives on the street are 14's and it looks like there's a decent amount of width and sidewall. (Couldn't find a reference to exact size.) It has a Torque flight 727 that has a 1:1 high gear. I'm going to take a wild guess and plug some numbers for a 245/60R14: With the 2.71 gears, 55 mph = just under 2,000 rpm With the 3.73 gears, 55 mph = just under 2,700 rpm Theoretical top speed at 5,000 rpm : 2.71 gears = 140 mph 3.73 gears = 102 mph I could be way off on my tire size estimate.Jerry From LA wrote: If I recall, this car ran 14.70 with a 2.71 rear gear. The 3.73 should be worth about a second.Just wondering off the cuff.... not knowing all the other variables(wheel size, gear ratios, shift points, etc) any idea what this will do for top speed, mileage, and highway rpm.
Way, way, way off. They are 275/40/17's on the back on 17x10.5 FR500's. 
It's a 2.73 now, going to a 3.73. The 727 Torque-FLite is a 1:1 3rd gear. I will definitely lose some MPG's cruising, but it should accelerate much harder. It ran 15.4 @ 88 in 2nd gear with a 2.4 60' time. I turn 2,500 RPM's at 70 MPH in 3rd. 3.73's should get me 3,400 RPM's at 70. If I'm doing the calculator right, it should go 13.87@92 in 3rd through the lights with no other changes.
I am glad you are resolving this. You're literally a day's welding, a U joint, and a different driveshaft away from being back on the road.
Great to hear Javelin. It's always nice to know enough people to barter.
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