Gears vs Transmission

[enaberif]

So I did some inquiring and if I wanted to swap out the 3.73 gears to a 3.42.. this is the overall costs involved:
3.42 gears will run you $197.96,
bearing kit $106.92
and 4-5 hours labour $380-$475.

I can pick up a used 700r4 off craigslist for $150-200 if I watch carefully and get it rebuilt for slightly more!

No wonder a lot of people just do the transmission route!

[slugish]

you can get a 700 r4 buily for slightly more than 200.00 > tell him to move his shop to Virginia . My trans guy ( who has done good work for me before ) says it would be around 1ooo.00 - 1200.00 > thats including evereything - all labor of removing & reinstalling .

[Wild83C10]

Why are you going to switch from a 3.73 to a 3.42? MPG?

Your not going to get much of a 700R4 for that kind of price. If you want a 700R4 that is going to take a good beating without having any problems then you will be spending over a grand.

[enaberif]

Originally Posted by Wild83C10

Why are you going to switch from a 3.73 to a 3.42? MPG?

Your not going to get much of a 700R4 for that kind of price. If you want a 700R4 that is going to take a good beating without having any problems then you will be spending over a grand.

You try travelling on the highway with 3 speeds and 3.73 gears

I'm just looking at my options.

[N2TRUX]

Just for point of reference, regardless of what transmission your running the difference between 3.73 and 3.42 is 1-2 mpg. It "might" be a bit more with your current 3 speed. The OD transmission should give you better mileage than the gear change, but doing both would be best.

With that said, consider how many tanks of gas it will take to recover your costs. If you don't need a transmission, then the best bang for your buck would be a gear change.

I would search the bone-yards for a rear axle with 3.42 gears. Pop the cover, inspect for damage, replace the gear lube and go down the road.

You can buy used axles for a lot less than a gear or transmission swap.

[dswancutt]

I think Ken's idea is a pretty good one. My uncle has 2 79 c-10, and both are sixes with the 3 speed and 3.42 gears. I don't know if this is just a coincidence, or if that was the gear ratio for that set up. Either way, it is a good place to start looking. Most sixes of that era died from the intergral head crapping out, not being gutted pulling stuff.

[enaberif]

Originally Posted by N2TRUX

Just for point of reference, regardless of what transmission your running the difference between 3.73 and 3.42 is 1-2 mpg. It "might" be a bit more with your current 3 speed. The OD transmission should give you better mileage than the gear change, but doing both would be best.

With that said, consider how many tanks of gas it will take to recover your costs. If you don't need a transmission, then the best bang for your buck would be a gear change.

I would search the bone-yards for a rear axle with 3.42 gears. Pop the cover, inspect for damage, replace the gear lube and go down the road.

You can buy used axles for a lot less than a gear or transmission swap.

Yup that was basically my next train of thought to find a old rear end all together and swap it in.

[mrh33916]

I don't know how much acceleration you're willing to give up but a used 3.08 for a couple 100 bucks found in many later model trucks would would work good on the interstate without changing the transmission

[C-10volvo]

I agree with Ken idea of finding a used rear with 3.42 or even a 3.08 gear set. Ultimately, if you're looking to spend a grand for better fuel efficiency, buy an econo-box!

Edit: yay for finally breaking 1000 posts!

[enaberif]

Originally Posted by C-10volvo

I agree with Ken idea of finding a used rear with 3.42 or even a 3.08 gear set. Ultimately, if you're looking to spend a grand for better fuel efficiency, buy an econo-box!

Edit: yay for finally breaking 1000 posts!

Oh I'm not looking for fuel efficiency as I know with a v8 and a 4,000lb truck that doesn't exist.

All I'm looking for is to drop my rpms a bit on the highway and gain a bit of mileage.