i mainly stay in the city cuz im still in highschool/ have a job after school, but some weekends i go in the woods and hunt, but as far as mudding goes i do it sometimes but i wouldnt call is my mud truck. i dont go on the highway that often neither so if i could 75 steadily without horsing the engine i'd be happy. also with acceleration would be nice to to be able to put someone back in the seat. but i dont expect it to be a drag truck

 

also how do you re calibrate my speedometer???

 

Lots of good advice here. If you are happy with the look of the lift and the 35" tires, your best option is to re-gear. I would look to see if 4.30 gears are available for the front end; I know they are available for the rear. If you can't get 4.30s, I would go to 4.56; it seems like a lot of gear, but with tall tires and overdrive, it will be perfectly okay. You will make much better use of the engines power and torque by having it in a usable operating range.


I personally would do gears before considering an engine swap. The 300 is a good engine, and very long winded.

 

yeah im really lad with the advice ive gotten from this threat. the only thing im not sure of is what gears. im contemplating between 4.56's and 4.10's.... my only real concern is like i said before, how they will affect my top speed, stress on the engine

 

What's a PSOM and how do I "P" it?

courtesy of Steve83

 

I already told you your rpm at 70 with 4.56's. The very popular majority has told you 4.56. Your not going to hurt that 300 i6. You lug that m5od around to much you may start having issues. Will 4.10 get you by, sure. Will you be happier with 4.56, without a doubt. If you ever hook up a boat or something to the truck, you will kick yourself in the butt for not putting in 4.56's.

 

They came under geared from Ford with that 3.08 ratio, now with 36's it's rediculous.

I use to have 4.56 gears with the old 4 speed now with overdrive you should enjoy those gears a lot!

 

My '87 Bronco ( 302, C6, 3:55 gears ) from the factory would cruise down the highway all day long at 3000rpms. It was kind of a dog from a stop after the 6" lift and 35" tires. I went with 4:10 gears to get me back to stock but 4:56 probably would have been a better choice for off road use. That doesn't matter so much after the swap to the 392 after the 302 died with 295K miles on it.

Driving it like an old lady (short shifting) isn't helping things either. You are constantly lugging the engine making it work harder.

 

Top speed is a moot point. Right now with the pedal on the mat in high gear, you can't get anywhere near your theoretical top speed. The engine just doesn't make the power, and it takes forever to accelerate anyway. With 4.56s and 35s the truck will probably have a higher top speed because the engine will be in a more appropriate rpm range to use the power.


As far as stress goes... the 3.08s you have now are stressing the driveline. You are giving the engine, transmission, transfer case, and differentials a huge advantage by re-gearing. The additional mechanical advantage will actually lower the stress in your driveline under normal operating conditions.


If you jump on a bicycle and try and pedal off with the bike in high gear, think of how hard your legs have to work, and how long it takes to get going. How much less tired will your legs feel if you try and pedal off in a more appropriate gear?

 

i have a 94 302 and a 92 300 so i will weigh in a tad here.
302. decent motor, i personally think it should NOT be in a truck, for me it just needs too high of rpm to get things done to my satisfaction.
300- low rpm motor, i think they will rev to about 5300 rpm but anything above 3500 rpm if just alot more noise, the power isnt there, and it never will be there. for daily driving and what i tow the 300 wins, sure the 302 will out accelerate it when unloaded and the 302 can have all the rpm it wants. but its when you have an enclosed trailer going up a hill when the 302 loses rpm and falls flat on its *** is where the 300 really shines. i am not sure if there is a difference in trans programming with the 302 and the 300 but in my experience the 300 will pull down and LUG WAAAAYYYYY more than the 302. the 302 likes to downshift, and thats fine i dont expect to pull everything in overdrive ( as a matter of fact with my 302 i rarely get to pull anything in overdrive ever) but once again as soon as that 302 loses its rpm from the downshift it takes its ball and goes home, leaving you waiting ( and slowing down even more) until it can downshift yet again to start the process all over.

all in all i think either one can be reliable, the 302 is currently at 224k miles with no rebuild but i can tell it is getting tired now ( it was bought new in the family and i have used it since 25k miles) my 300 has 135k miles on it and seems as fresh and as healthy as when i drove it off the showroom floor.

so for a summary
302- for overall power potential and ability to go fast, needs rpm to do anything
300- built like a tank, low low rpm motor will go on for ever.
351- more power than both and inbetween the 300 and 302 for reliability, has the most power potential of all 3

 

ok guys thanks now what about brands? im assuming you can get 4.56 gears from a lot of places but what are your guys' thoughts???

 

i understood most of it but some of it just kinda seemed a little over mmy head when it was talking about grounding the wire and what numbers you need and stuff like that lol. how much would a mechanic charge to do it?

 

Most mechanics are going to have zero idea of the process and why it needs to be done. I would not pay someone to screw up the calibration.

The key items you need to calculate the constant is the revolutions per mile of the tires on the truck. This is usually listed at the manufacturer's website.

Plug that into the formula: ConvConst = RevsperMile x ToneRingTeeth / 8000

For your truck the tone ring tooth count is 108 so the formula becomes:

ConvConst = RevsperMile x 108 / 8000

So now all you need is the revolutions per mile of your tires.

 

ok that makes it much easier to understand lol, what about actually callibrating the speedometer?

 

I've never done it, but here's another thread with a step-by-step that might help.
https://www.ford-trucks.com/forums/1...eedo-gear.html