I have a 78 F150, 300I6, 4x4, 4 speed (with granny),Short Narrow Bed.

We have this truck and also a 97 Explorer. With 2 young children, anytime I need to go somewhere I leave the Explorer with my wife and I drive the truck. Sometimes for work I need to drive to St. Louis or Kansas City (I'm located down around Joplin and Springfield Missouri...KC is 2.5 hrs and St. Louis is 4 hrs from me).

I'd like to make some modifications to my truck to make it more "interstate" friendly. I don't pull anything with it and I very rarely go off road in it. 99% of my driving is around town and on the highway. I've been told that the only way to get my truck to drive better (not so much like an old farm truck) is to put a "car" transmission in it.

So I'd like anyone's suggestions as to how I can modify my truck to make it drive better.

How do I figure out what transmissions are available and whether or not they will bolt up to my transfer case? If I swap the engine or transmission I'd like to not have to also swap the transfer case, but I'm open to all and any suggestions.

Thanks,

Chad

 

well, you could put taller gears in it for interstate driving.. maybe 2:73's insted of the 3:50's your's probably has.. be kinda like an overdrive, but in all gears.

 

Are you meaning the motor is pretty wound up out on the highway? What is your axle ratio? You could swap to higher (numerically lower) gears, but you'd have to do both the front and rear since you're 4x4. A "car" transmission will be a lot weaker than what you have now. If overdrive is what you want, an overdrive truck transmission would work, but can get expensive.

I'd say go for higher gears. I have 3.08's and they're not bad at all on the highway with no overdrive, and not at all "gutless" like some people say.

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1995 F-150 Supercab XLT 155" 4x4 M5OD 302
1986 F-150 4x4 NP435 300

 

You can really cook along with some 2.73's on the freeway, but you'll also be a dog off the line. Here's the catch, good luck finding the higher gear ratio for the front axle. You need to define driveability...meaning speed, acceleration, handling?

 

[updated:LAST EDITED ON 01-Oct-02 AT 11:15 PM (EST)]When you say interstate frienly do you mean go faster at a lower RPM? or just smooth out the ride? If you are talking lower rpm's you can also sometimes go with bigger tires, It will trow your spedo off a little but will gain you ground speed. If you ar talking about a rough ride or hard to keep on the road, start looking at front end parts(ball joints,u-joints and shocks...

 

Bigger tires make a very small difference. The axle ratio change will help more. If you have enough room you could add an overdrive unit in the drivetrain to the rear axle instead which is more usefull. Just remember to disengage the overdrive b4 you put it in 4x4 mode :-)

A good set of P235/75R15XL radial tires will improve ride. Remember, don't let a tire salesman sell you anything but the Xtra-Load tires. There is more to tires than simply dividing the vehicle weight by 4!

Another thing to do is replace the spring eye and shackle bushings.

Otherwise the steering can be improved by replacing and repairing parts to tighten it up.

 

Thank you to everyone for their responses.

Let me try to further explain and give some answers to the questions that were raised.

I currently have 3.50 gears and 32inch tires. I'm going to be replacing those with 33 inch tires when the time is right. I can't go any larger with out lifting it some and I don't want to lift it because it won't fit in the garage.

The steering used to be pretty sloppy but after replacing the bushings that is fixed.

What do I mean by "drivability". I'm not looking for a hot rod or a rock crawler. I'm just looking for a good highway driver. I want to be able to drive for 4-5 hrs at 75-80 mph and not feel like I'm pushing my truck to it's limits. I'd like to keep enough acceleration off the line that I'm confident to pull out into heavy traffic if needed.

Currently I don't have acceleration or speed and the handling is fine but not exceptional. I have the granny first gear which is great for pulling things (something I NEVER do). I currently take off in second gear which is fine, but it doesn't perform well at all off the line.

I want to figure out what kind of $$$ is involved in changing out the transmission. I'd like to have a 5 speed or a 4 speed without the granny gear. I do not know how to figure out what is available that will work with my current engine and transfer case.

I have to make these trips for my work. I can't afford to be limited to 60-65 mph on the interstate. I love my truck, but I'm trying to determine if it is possible and how much it will cost to make it drive the way I need it to. If I'm looking at spending an arm and a leg on it then I'll have to get something else to drive. This is not a "project" or a "toy" it has to be my daily driver. I'd love to fix it up and really make a nice truck out of it, but if it is always going to drive like a farm truck then I'm not going to sink the money into it.

Options I'm considering:

1. Change out the transmission. Question: What 5 speeds or 4 speeds (without granny) are there that will work with my transfer case?

2. Change out 300I6 to a small block V8, Change transmission and if necessary transfer case. Questions: What kind of price tag am I looking at (I realize a lot is involved...a rough estimate is fine)? Would you go with something from the same time (1978) or would you find something newer? If newer does that make it a lot harder or more expensive?

3. Buy a little ranger pickup or perhaps a mustang and sell my truck. I don't like this option, but I'm considering it. HELP me keep my truck.

Thanks,

Chad
1978 F150 4x4 flare side 300I6.

 

find a newer truck, a 4x4 that is wrecked, but low miles with a efi 302 or 351w with a 5 speed overdrive tranney and swap everything into the old truck, then you would get what you are lookin for. Not sure on prices as they vary by location.

 

I wouldn't go with 33's if you want highway manners. If you want a better tranny with a usable 1st gear get a T-19 out of a bus or breadtruck. The T-19 and the T-18 you have share the same case. A good transmission shop will be able to mount your transfer case to the T-19. The T-19 is a 4 speed with synchro's on all gears. Then get an overdrive or a range splitter set up. The 235/75R15XL's will give you decent highway manners. I used to run 70-75 MPH with a 300-6 with an AOD getting 16-17 mpg in an E150 club wagon van. I wished for a manual overdrive, the auto kicked it out of OD far too easy.

-or-

Go with the late model running gear, but then you will probably have to deal with 'puters...