Best gear ratio for 4 speed, highyway and pulling..

[sle2115]

I've had both under my truck. It came with 3.55's and I swapped to 1 ton 4.10 axles. My truck ran good with both, but for my uses (hauling and pulling stuff) the 4.10's work great. Mileage definetely suffers on the highway, but I don't do that much anyway. I think 3.73's would be about the best compromise. When I had the 3.55's and hauled wood for the club, which is up a very steep grade, I thought I was going to have to shift into low range to make it. It actually just ran out of go, but never stopped going. I have the 4 speed as well. Since going to the 4.10's, I walk up the same hill hardly touching the throttle, just let it crawl along. Out on the highway, well, on the 65 MPH ones (read 70+ MPH) it really talks to you and LOVES it's fuel, but that's rare for me. I guess the thing you need to figure out is what the majority of your use will be and decide from there. I don't drive my truck everyday, or on the highway much, so it doesn't really bother me that it likes fuel because it seems like it would pull a house or two, which is what I need most.

 

[69oiler]

i like the 3.55 gears in the older trucks without overdrive myself, except for starting off the line. here's a pic of my former F250 with the 6.9/T19/3.55 gears and a load of firewood

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and here's a 0-70 run that same day with that same load. you can see it bogs at take off.

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my take is that with the 3.55s you can use a lower gear if you need more power, but with the 4.10s you are stuck with a lower comfortable cruising speed. my current truck has 3.55s and a C6 and there have been a couple times when i was starting up a hill towing, and i wasn't sure if it was gonna go or not from a stop. i think the turbo will take care of that problem.

but in your case if you are going to truck pulls then it's a no brainer, turbo or not you want 4.10s.

 

[david85]

Thats basically what my truck was like with the C6/3.08 naturally aspirated. It jsut seemed to run out of steam by 45 MPH. Still pulled well after that, but no the seat of the pants that you get off the line from the low end torque.

What might help for those that are running C6 tranmissions is to replace the gears with a set from the later E4OD. The 1st gear ratio has about 10% more reduction and second gear about 5% advantage. I did notice a difference bweteen the C6 and E4OD transmissions in the low speed start offs and operating on boat ramps. This is not always practical, but if are in a situation to overhaul the C6 anyway than it might be worth considering if and when the time comes.

If you use the 6 pinion steel gears now available for the E4OD, than its as bullet proof as you can get.