Guys,
I am interested in finding out if i can achieve 15 MPG buy transplanting a 300l6 or a 302. right now as my truck sets it gets about 8 or 9 MPG with a 390 and an automatic transmisson. so since the truck orginal was a standard i am thinking that if i went back to the manual tranny and a straight six i should get at least 15 mpg. what are yalls thoughts or suggestions. also i want to add power steering on my truck. my wife complains because she cant turn the steering wheel on the truck. well guys any help i can get will be great i look forward to restoring my truck.

 

I dont think 15 with the I6 is out of the question with the right tire and gears combo and a light foot. Back when I had 31s on my truck and my 390 was fresh I would consistantly get 12-13 at 60mph.

 

Either the 300 or 302 will get you there, and both can be found with an AOD automatic trans. Try to find an '88-'93 trans from behind a V8 car or in a truck. These are not strong transmissions, but the later models have many of the issues fixed, and beef up parts are available.

The 300 develops torque just off idle, but is pretty much all done just after 3000 rpms. The 302 is softer on the bottem end, makes a tad bit more torque but at higher revs. Depending on which 302 you get, it makes more hp or a lot more hp. (truck model 180 or so, Mustang or Mark VII are 225 horse)

So shop around. I would look for an existing combo and try to get the entire pkg. One problem here is the '88-'93 trans is going to be hooked up to an EFI motor, so perhaps you shop separate.

Do some calculations based on your axle too, make sure whatever you get will pull the od, or if you are geared really tall, you can go back to a C4 trans w/o OD.

Adding PS along with this will be done more easily if you find a donor truck of the same vintage. I don't know if your year had integral or linkage assist. If linkage assist it may be possible to adapt integral PS via a new box. Since you're pulling the motor, plenty of room to work. This is an example, but for '53-'60:

http://steeringandbrakes.com/store/p...&products_id=3

Maybe it will work, or perhaps there is another answer.

 

Consider this: How many gallons of gasoline you can buy with all the money you will spend to maybe get a couple of extra MPG?

These trucks have the aerodynamics of a brick, 105 octane premium gas was 30 cents a gallon back then, and no one gave a damn about gas mileage.

Pouring money into these trucks to try and achieve better gas mileage, IMO is a waste.

The 2008 far more fuel efficent and aerodynamic F150 V6 gets about the same mileage a 40 yr old truck gets.