Folks,
This is my first post on these forums although I have been an avid reader for awhile now. Quite frankly I am posing my question here because I have come to appreciate the knowledge and wisdom of this forum!
I have a 1989 F-250 4x4 regular cab 5.0 302 5 speed manual/355 gears with 74,500 original miles. Other than some fuel pump issues (dual tanks) this truck has given me wonderful service for the last 20 or so years. I now have two young sons and we enjoy riding atv's. Here is where my issue begins....My truck really struggles to pull a 1200lb utility trailer with two atv's which give it a grand total pull weight of approximately 2200-2400lbs. Its so bad I feel like a traffic hazard as the low end is miserable, and just a rise in the road(not a hill or for heavens sakes mountain) causes immediate loss of momentum. Everything on the vehicle is original, as I have never modified any aspect of the truck.
I have been told changing the rear end to 410 gears would probably show me the most improvement for my tasks at hand. I have also had a K&N Cold air induction in conjunction with a hypertech chip and lower thermostat suggested. I really do not want to get into cams/heads or internal engine issues if I can avoid them.
Back to the 410 gears. I checked with Ford and they have discontinued these gears for my year of truck. I was able to determine my truck has a Dana 60 rear end 10.25 (355) and a Dana 44 (354) front differential. Guess I would like folks thoughts on my issue as well as any other suggestions you feel may help me with this problem. One other issue...if not Ford WHO/WHAT brand of replacement gears do you suggest? Any help provided will be greatly appreciated. Thank you in advance for your time!

 

yukon gear is a quality decent priced gear. find out what rear axle you have for sure before spending any money, should be a sterling 10.25 semi float. to be honest about your problem, it's the 302 under the hood that's gonna hold you back. i'm sure 4.10's would make an improvement, but i don't think it will be as big of a difference as you want, and welcome to fte

 

Personally i think the gears will help alot but if you still have trouble out of the truck find a decent 5.8l 351w to swap into the truck you can use the flexplate off the 302 and all since its manual

 

Where you live?

I have rear axle it 4.10 it came from 91 F250 it should be match.


First try 4.10 before swap engine.

 

an exhaust would do you some help too

 

Thanks for the "Welcome" FatDan....Milwaukee I live in Lynchburg Virginia.
With so few miles on this block and the body of this truck being nearly perfect, I hate to change the original engine. I am not looking for a "stump puller" I realize the 302 has its limitations, I just want to avoid the traffic hazard /emergency flashers on every rise in the road I come too. Once again thanks in advance for all ideas/suggestions.

 

Your rear axle is a sterling 10.25", not a Dana 60.

Gears will help but you are going to need to change both front & rear gears if you ever want to have a useful 4x4. You will probably spend between $800 and $1000 getting both axles done. You will also take a mileage penalty with the lower gears.

The real problem is the 302 under the hood. A cam and exhaust will help some, but there is no replacement for displacement. The 302-powered F-150's are somewhat underpowered and I can't imagine how bad it must be in an F-250 towing anything.

If you swap in a 351w with a cam and exhaust upgrades the weak point is going to be the transmission. It's the same tranny used in the F-150's and even some v6 Rangers. It's not a really strong unit and I don't know how long it would last in between a mildly build 351w and a 2500 trailer. There is a stronger manual available but it's hard to find in a 4x4 smallblock bell pattern for a reasonable cost.

If it were my truck, I'd be struggling between selling it and finding something better suited to your needs and spending the money to upgrade the powertrain.

IMO Ford should be embarrassed for building a 3/4 ton truck with a 302 and the M5OD transmission. It borders on the stupid.

 

dear lord! andym and i agree on something. contact your local holy man, it must be the rapture

 

Yes i agree honestly i think if he wants to get the best setup for that truck he should either go with a 351w with a zf tranny or a 460 and i really dont know what tranny i would go with on that

 

To work with what you have, ditch the K&N intake and the chip.....worthless garbage. Use the 300/6 - 460 stock air intake tube, long tube headers with 3" single exhaust, try a electric fan to free up a couple of hp..........If you want to go further, Conanski can give you excellent advice on cams and GT-40 heads that will really wake up the 302.......Otherwise, you can trade for a 351-460 powered truck and not even know that trailer is back there.

 

or swap in a cummins...just sayin-- FordCummins.com: '80-'97 Overview

but if you want to keep the 5.0 ditch the hypertech chip, and add headers and add a full exhaust, maybe underdrive pullys or electric fan, then i would think about goin from your k&n to a 300 or 460 intake im not sure if that would be better than the k&n

 

your F250 shouldn't be having an issue pulling the weight you've posted, and the 5.0 is a decent power plant, plus you have the advantage of a stick. I'm not saying you don't keep up on maintenance but I'd say do a full tune up with fuel filters before doing anything drastic like a rear end/gear swap. It's EFI so a bigger carb wouldn't be a good recommendation...perhaps a bigger throttle body, with a rally big induction tube, I used PVC on my 91 F150; or bigger injectors, and headers. Your fuel mileage will suffer if you change up to 4.10's.

I'm not you and I don't know what you have for shop tools but I'd stay with engine management personally. Also I'd want to keep my 15.6MPG with the 3.55's rather than go with 4.10 and drop down in MPG.

 

Lower thermostat?How low?If your motor isnt getting up to operating temp,the computer tells it to run rich,making it run like crap.I made the same mistake when I was 16,(put a 160 degree stat)and it ran rich costing me a catalytic converter.I would look into bad egr,clogged cat,clogged fuel filter,or too low temp on thermostat.You should be able to pull the load your describing with a half ton v-6.

 

+1 for what 93coleman said, now that i think bout it moving that weight shouldnt be hurting you so bad even with the added weight of the 5.0 being in a 250

 

+2, while not a power house that weight shouldn't slow it down that bad, not if running right.

As stated to low running temp is a bad thing, running rich all the time can and will cause excessive ring wear. Your thermostat choice may not have been low enough to cause problems but check all as suggested. I'd include a compression check with that just to verify its up to the task and no damage has occurred. If the compression is low across the board it won't mater what else you do, so its a good place to start.