1987 c10 manual 4 spd.. factory trans?

[1976gmc20]

Originally Posted by Tom

That's not normal. They have the same final drive ratio. By bypassing the compound low first gear your getting the same number of gears to accelerate threw. You should get about 10-15% better mileage, not 50%.

The number of gears isn't the point.

I think the torque converter on the old TH350 just sucks out a lot of power, and as I remember the shift points were really high compared to the 4 speed overdrive automatic in our 1991 Suburban. Like I said, they were really good at converting gasoline to noise

Apples to oranges. I had a medium to large size cam, RPM intake, holley 750DP, MSD iginition, headers with dual exhaust, 275/60/15 tires, 3.73's,385 stroker, vortec heads and 10:1 compression in the 78. Yes, the 79 with the vortec 350/200-4R got 15mpg on the freeway, but city mileage never changed. Besides all that, how is accelerating to final gear by 20mph at all fun?

Fun ???

Well, my pickups have always been work pickups, and most of that ends up being on back roads. No big hurry just to get to 30 mph. Of course when towing a big load, you have to run them up a little faster in each gear before shifting, especially up hill.