Which Way To Go??

[LDO]

1957 3100 with a 283. Truck will not be used to haul or tow. Just want a reliable cruiser that can ride thru town or jump on the highway without worry.

Current set up is a TH350 with original 57 rear and 3.90 gears.

40-50 MPH = about 2500 RPM so I usually just stay off the interstate and even in town, my gas mileage is suffering.

My question is should I go with a different (6 lug) rear end or keep it and swap out the TH350 for a 700R4.

Would like to hear all opinions and advice.

Thanks in advance.

[Kim57]

If your looking for better mileage I think the transmission swap would accomplish it better than a rear gear swap.
IMHO if you do the gears only your going to see a drop in driveability around town.
The best case would be to do both.
Just as a reference my brothers 62 f**d with a modular V8 has a 4 speed auto with 3.25 gears and gets 20 mpg and is real easy to drive around town and on the highway.
Kim

[OrrieG]

Change the transmission. 4th gear is .70 so your 2500 rpm will drop to about 1750. Also has a lower 1st gear for quicker off the line response.

[mr48chev]

The trans change would probably give you the best all around driving truck. It would have decent highway manners but still be able to pull a trailer or have good low end acceleration.

[pro1955]

I went with a early Camaro 10 bolt 273 gears, with a turbo 350 I run 70 on freeway all day long. Easy to find, 2" narrower than stock so you can run a deeper rear wheel. Will need to install new spring perches but you will need to change things to run 700R4, more cost effective I think to do rearend. Oh yea it gets alot better mileage too, my driveability is great around town, will do a first gear burnout.

[LDO]

Originally Posted by pro1955

I went with a early Camaro 10 bolt 273 gears, with a turbo 350 I run 70 on freeway all day long. Easy to find, 2" narrower than stock so you can run a deeper rear wheel. Will need to install new spring perches but you will need to change things to run 700R4, more cost effective I think to do rearend. Oh yea it gets alot better mileage too, my driveability is great around town, will do a first gear burnout.

thanks but it would have to be a 6 lug rear. Not sure what the results would be with getting the 5 lug axles filled and re-drilled although it is an option...

[northerngmc]

You can also purchase a 3:38 to 1 ring gear and pinion for your stock rearend.

http://www.yukongear.com/ProductDetails.aspx?ProdID=823

[Dan in Pasadena]

Originally Posted by pro1955

I went with a early Camaro 10 bolt 273 gears, with a turbo 350 I run 70 on freeway all day long. Easy to find, 2" narrower than stock so you can run a deeper rear wheel.

Pretty sure this is my gear ratio too. I have a (too) cammed 283 with Edelbrock dual plane intake and Holley carb, headers. 10 bolt rearend and I can freeway drive with no issues at all. Older Chevy 5 x 4-3/4", 5 lug pattern.