I've been thinking about long-term plans for my '87 F250 and I think for now I'm going to stick with the 351W and automatic.

Because this truck is my daily driver I'm looking to see where I can get some better mileage.

I believe the truck has a 3 speed. I'd like something like a 5 speed with a decent 5th for highway drives. The truck will tow an enclosed car trailer every other weekend.

 

The only auto options with OD are the all mechanical AOD and the computer controlled 4R70w and E4OD. All of these are 4 speeds. The AOD is a light duty trans and not recommended for heavy hauling, and while the 4R70w will bolt up it was never factory installed behind the 5.8 so you won't find a factory 5.8/4R70w PCM for that combo, you have to use a stand alone controller or a MAF 5.0 conversion. The 5.8/E4OD combo was common so it should be no problem to find everything you need to do a swap from a donor vehicle, and the '94+ trans has upgrades to fix several common problems afflicting the early versions. An aftermarket controller is also an option with this trans.

 

Your truck likely has the original 3-speed C6 transmission. To be honest with you, I don't think you'll find any easily-sourced automatic transmissions with more than 4 forward gears. Your truck did not come with a computer-controlled transmission, and all the 4-spd automatics that came in later trucks are computer-controlled. That means you would need some kind of control module. It can be done, but I don't know enough specifics.

 

Your best route will be to use either a 4R70W or an E4OD with a 3rd party aftermarket transmission controller.

 

You can probably buy a lot of gas for the price of this conversion. Do you drive enough miles to save enough to make it worth while?
JERRY

 

adding an auxiliary overdrive is another option, google "laycock OD", its the same archetype as gear vendor, so much so that the parts interchange and gear vendor supports the unit. they came on old manual Volvo's, if you can find one....all you need is a switch and an adapter from gear vendor. Or, just order a kit from gear vendor.

 

Well there are also other benefits, such as longer range on a tank and less noise and wear on the motor while cruising.

Assuming a 4-speed lockup transmission takes him from 9 mpg to 12 mpg, and he drives the truck 10,000 miles a year, he would save almost $700/yr on fuel.

The swap would pay for itself in 2-3 years.

 

The truck is my daily. Around 40km round trip everyday (25 miles).

The 4R70W looks like the best option for automatics. The whole reason I'm staying away from manual is purely because I'm lazy. I've driven manuals in traffic before and it sucks.

I might just pick up a second car and park the truck. She needs some TLC anyways. Maybe I'll do the transmission when the time comes.


Thanks everyone for the advice

 

I was a daily pickup driver for many years and thoroughly enjoyed it, it was my only vehicle at the time. But when I met my current girlfriend/spouse I started driving her Subaru and this was a major eye opener. Using the car to commute to work about 30kms a day I was only using about 1/3 as much gas compared to the truck so I was filling up every other week instead of every week and putting on more miles at the same time. So my suggestion is if you get another vehicle maximize the gains and get something really fuel efficient.

 

im in the same boat have a 87 351w c6 and no doubt the c6 is good the real option for a truck like this is the aod and have it built up more with 4r70w gears because those controllers are about 2k and would be my first choice but the aod out of a truck or van i think 91 is a good year and servos are stronger with revised valve body and sky is the limit with these as well they have all hardened options for aftermarket one piece input shafts and internals then it will be far more then light duty but as is im sure it would hold up for your use.

 

The controllers aren't 2k. You can get a complete U.S. Shift setup for like $700 or less.

 

Or just get an aux od for your c6.....

 

An auxiliary overdrive unit still doesn't get you lockup on a C6.

 

Nope, but a little searching gets you od for a few hundred bucks.