Ok guys, heres the situation. Im about to do a chit ton of work to my trucks, and im not set on which end route i want to take yet. thats where all you fine folks come in. Ill tell you my situation, you tell me what to do next

My baby is my 89 F250. It has a 351W and 4" suspension lift. My DD is a stock 93 F350 N/A diesel. Both trucks have 4:10 gears. I want that solid dana 60 under my 250.
My plan is to swap complete front suspensions from one truck to the other (axle, springs, shocks, brakes, steering, etc) I will run the stock leafs under the 250 until tax time, when i think it will get a RSK to level it back out again. If my measurements are correct, the 4" ttb lift will put my F350 dead nuts level with the stock rear suspension.
I will shortly here be aquiring a 93 F250 N/A diesel for parts w/ taller axle gears. (Not sure what ratio yet, but current owners tales of 20mpg and crappy towing power tell me taller than my current 4:10s).

Heres where my indecision comes in. On my F350 should i stick with the 4:10s and add a larger tire (Im thinking 33ish) or swap axles completely with the taller gears, and still probably run a 33ish tall tire? end goal is whatever better mileage i can get, currently im at 16. I do not want to worsen mileage.

And just cuz, heres some pics of both the trucks im talking about:
F350


And F250 how it currently sits:

thanks for any help guys!!

 

Can't really speak to your gearing question, that's more about your preference, uses, and more important what trannies they have, you didn't mention that.

The bigger question I'm thinking reading that is why are you making the F350 a lesser truck, it sounds like the better platform to be improving, not taking good parts from?

 

all 3 trucks have ZF 5 speeds. I dont really haul anything, i got the diesel more for its fuel economy over any of the gassers than its power.
And im taking from the 350 because i want a dana 60 under my 89. the 89 is a pulling truck, a mud truck, a do anything i want to truck. until this past spring it was on 38" swampers, and at some point i would like to step up to 40s.

 

My suggestion would be to keep the F350 as it is. Find a donor truck to do your solid axle swap. This way you don't lessen the value of the F350. If you want better fuel economy and your dead set on having a diesel sell the F350 and buy what you want. I just see this as 2 major projects. The F250 vs F350 front springs are way different. Your trucks will ride like chit if you don't swap them. Heck I wish I could find a truck like your F350 and afford it.

 

I agree, its 2 major projects. What i have are time, tools, and space to work. I dont have alot of expendable income. This way i keep what i have, and get them both set up the way i want them. If the body on the parts truck wasnt in the shape its in i would just drive that, but its far too gone w/ far too many farmer repairs for me to want to risk that.

 

Could you maybe part out your parts truck to gain more extra money then what you bought it for? Then this way you could buy a solid axle for your swap. Sell some other items that you don't have a use for. I know trying to sell stuff is a pain in the **** but you might recoup more than you figure. I also don't know how much you have wrapped up in the parts truck.

 

Yes i plan on parting out as much as i can from the parts truck, but i still wont get anywhere near what they want for a D60 around here, plus all the needed parts to rebuild it. The swap is happening, sorry to disappoint.

As far as ride goes, rough country (the makers of my lift) bill the same leaf pack for all engines. Im hoping the extra weight of the diesel allows a little more flex than my 351 did.

 

No disappointing here. I wish you all the best and look forward to the build thread.

 

Sounds like you have a solid plan. If I get what you're saying, the springs will go with the axles, so that should keep things comfy. What 83capril is saying is that running a D60 on TTB springs is a bad idea, and I completely agree! But that shouldn't be an issue if you're moving the D60 springs to the 250 with the axle.

There may be some slight differences between the frames, mainly I'm not sure if the F350 frame will have the holes for the TTB brackets. But having both trucks side by side shouldn't make that too much of a problem. Because of this, its going to be easier and faster to get the D60 under the F250 than getting the TTB setup under the F350.

If I'm reading this right, those are your only 2 vehicles, so you need to have one drivable almost all the time. So what I would do is strip what you need to off the F250. Then drop the D60 keeping everything you can attached, and roll it under the F250 and bolt it up. That should only take a couple hours. You can leave the springs on the axles, just remove the bolts at the spring ends. Pull the pitman arm off the steering box, leave everything else attached. Unbolt the trac bar bracket from the frame, and if you have a sway bar do the same. Unless I'm mistaken, the calipers are the same, so pull the tire on each side, pop off the calipers, and tie them up, then put the tires back on. Roll it under the F250, bolt it all back in place and slide those calipers back on.

The worst part will be getting the spring bolts out of the bushings as they tend to rust in place. If I'm right about the calipers, you don't have to open the brake system up which will save some time.

 

Yup youve got it right, thats the plan. They are not my only 2 trucks, i also have the silver one in my avatar up there ^^^^ but im starting this project at work after closing at 5pm today, and its gotta be done by start of work monday morning.
Brake calipers are going to be an issue, originally my 89 came w/ a D44HD, and i swapped in a 95 D50 6 years ago. so its got the updated, bolt on calipers. As long as the hoses work, im just gonna unbolt them and rebleed the brakes. I took a quick look under the F350 frame, and i saw alot of extra unused holes in the cross cradle, so im hoping theyre all there.
What are your thoughts on the 4:10s or 3:55ish gears?

 

My truck has a ZF5 and 3.55 gears. My mileage isn't the greatest, and tends to vary. Sometimes I top 16, sometimes its 14... My driving manner varies greatly from day to day, and while I tend to shift early and keep the revs under 2K unless I'm on the highway, I don't really follow any other hypermile strategies... The truck has no problem getting up to 80+ on the highway. However, when towing it tends to fall flat on its face up hill.

I'd say if you're going for daily driving and mileage, 3.55's might be better. But if you'll be towing often, 4.10's may be a better fit. I'm sure others on here have much better advice on this one!

As for the brakes, I had wondered when they went to the bolt on calipers (actually I'm still curious if anyone knows...) which is why I wasn't positive on it. I have no clue if the hoses are the same or not, but can't imagine why they would need to change that unless the bolt on calipers are a complete redesign from slide pin ones. Worst case scenario, you disconnect the hose where it transitions to the brake line on the frame. There is a much great risk of that being rusted up and busting a line, but they would have had to be smoking something if the engineers changed that connection too. By worst case scenario, I mean you break the line trying to loosen it and have to replace the hard line and the hose, which isn't terrible, but does slow you down a ways.

 

The only thing i tow is a pop up camper in the winter. Now owning a diesel i would like to be able to trailer my 250 to mud bogs and truck pulls, but that would be few and far between, only on the weekends. Rare enough i could deal w/ taller gears. How would 3:55s fare with a 33x12.5 or a 35x12.5 (305 or 315?)