I've just gotten my first truck with a 460. Its a 1991 f-250 4x4 extra cab. The power it has down low is incredible. But when on the curvy hilly roads of central Missouri, it tends to get pretty bogged down towing trailers totalling about 6000 lbs. It has manual 5 speed tranny. Is there anything I can do to give it some more power when towing?

 

What gear do you have in it?

 

As in rear end gears? How do I check that? Im kind of a newb at this.lol

 

that, but he meant (i think) more "what gear are you in when it boggs out" 5th, 4th, ect,ect on your shifter

 

Keep the 460 at least 3000 RPM at 60 MPH under load and it will pull fine in it's stock form if all is ok.
Only thing you need is to put in in the correct gear and RPM for the load applied .
If it is below 3000 you are in the wrong gear!!
Also make sure you have around 45 PSI of fuel pressure if it is under a load.
Before you start changing anything mske sure the engine and fuel systems are up to par.
By the way, a loaded trailer should be pulled at 55 - 60 mph to keep things safe for all concerned.

 

Well one problem I have is that the truck has no tachometer. It usually bogs down in 4th at around 45 I'd say. I don't know how to find out my rear end gears....

 

dont have a gas motor but 3rd gear should be about right at 45 when towing. There should be a sticker on the drivers door jamb and one thing it will have is the axle code. Here is a site that will decode: What is my Ford rear end ratio, do I have positraction? - Drivetrain.com

 

cold air intake system , chip or program for computer !

 

You can pick up a small Sun tach from Autozone for cheap. If you're like me, it will take you longer to decide where to mount it than it does to actually do the install.

As far as checking what gears you have, you can look them up from the door tag as bashby said, or check the code on the rear axle tag. If it's possible that the gears have been changed over the years by a previous owner, do the following:

Chock front wheels.
Place the rear axle on jackstands.
Put trans in neutral.
Make a mark on the driveshaft and a mark on one of the rear tires.
Count the number of driveshaft revolutions required to make one revolution at the tire.

~3 1/4 revolutions = 3.27's or 3.31's
~3 1/2 revolutions = 3.55's
~3 3/4 " " = 3.73's
~4 " " = 4.10's

Etc., etc.

 

Oh cool. I didn't know about all those ways to find out. Well, the rear end tag was really rusty. But I think the closest I saw was something that MIGHT have said 3 L 55. This is the sticker on the door jam. Here is a link to a pic of the sticker. truck tag | Flickr - Photo Sharing!
What does it show? I dont see the gear ratio on it.

 

The 3L55 on the axle tag and the "C9" under the axle code on your door tag both say that the truck came from the factory with a 3.55:1 Trac-Loc (limited slip diff).

 

So is that a good thing or is that part of my problem?lol. And what does the limited slip thing mean?

 

3.55 is fine for cruising down the highway and light towing. Despite the fact that the 460 has incredible low end torque and the fact that you have a five speed, my personal opinion is that 3.55's are too low for what you're doing with the truck. Depening on how often you tow and how much highway driving (65-70mph cruise) I would recommend at least 3.73's if not 4.10's. Limited slip means that inside the diff there are clutch packs that limit slip between the two axle shafts, that means two black stripes on the pavement instead of one.

 

Yeah I meant what gears in the rear-end because my 460 has the same symptoms as yours but I have a 3.08 gear so I know that is where the problem lies - I'm gonna change to 3.55 in the near future.

 

Wow. Thanks a ton guys. You've been a big help. THIS SITE IS AWESOME! Jas88, why not get some 4.10s? I am gonna change to those I think.