New build - 1991 BornFree ford class B 7.3 diesel 4x4

[bugwhacker]

I changed my mind from my old build as I found a much better unit for me to convert. It meets my design criteria of being no wider than a normal van and if I take the wheels off it can be stuffed in a cargo container for shipping. I needed more headroom and I found a nice Bus to convert instead of the Falcon/B190 I had. The Falcon body only left me with about 4 foot that I could actually stand up in and it was narrow (4" at the top).

I would love a 4x4 Sprinter but this is what I can afford and it has a motor that will run on the diesel they have in other countries with no trouble from a modern engine. This body has just as much room as an EB Sprinter and I can still do the 1975-1978 round headlight conversion which I like the looks of.







Inside it is a big empty box which is perfect for me to customize. I found it in a junk yard and bought it for $1100 including a rear axle complete of my choice so I can upgrade to disc brakes. I don't know who they thought was going to buy it for the $2000 they had marked on the window. It runs okay and supposedly has a reman 7.3 IDI in it with an e40d transmission. I still have my 7.3 van with the pathfinder 4x4 conversion on it for my parts van so I should have most of what I need to fix it.

My van is a 1991 so no Ujoint style conversion for me but I can either do a body swap or move all the 4x4 parts over from my parts van. The parts van is an e250 and the BornFree is an e350 so I am leaning towards the 4x4 swap. The 4x4 is a Pathfinder conversion - so coils on radius arms. Is there a spring over conversion for these or is it all some type of link setup? I would really like to go to a D60 front axle but mine only has a D44 under it. Is there a coil over axle that will fit reasonably that is a D60 or am I stuck with D44 or going to a leaf spring front?

 

[bugwhacker]

My headlight ideas.

I bought the last NOS 1975-1978 lower valance that National Parts Depot had for $6 - that's right $6 but it took $23 in shipping to get it here in a massive box full of packing material like it was made of glass. Now I can move my turn signals down for my 4 headlight grill.







I am leaning towards the tube style grill as I can fab that one up all in metal but the other one is cut up 1975 plastic grills glued together.

Some would ask why 4 headlights? Well I like the look of it plus I can use whatever cheap 7" headlight I can find and with 4 of them burning it should be pretty good light without having to resort to HID type replacements which I dont remember seeing in any parts stores in South America when I was down there last year.

I have all of the XLT trim work to put on my Van except the front pieces on the nose. Anyone have a set they would part with?

 

[Bikersmurf]

With 4 Hella 7" headlights running 90/100W headlights, you'd be set for light on the front end... You could even run a mix of different bulbs so you don't blind anyone if you wanted less light. I've even seen 130 W high-beams... But they'd be overkill. I'd see if you can find an ambulance package alternator to power all your lights and accessories.

 

[bugwhacker]

As for an alternator I am replacing mine with a standard 130 amp big frame 3G alternator from a ford Taurus. I would love to run duel alternators but it doesnt seem like anyone has figured out how to do that on the IDI v-belt setups without giving up AC which is not an option for me. I am trying to keep things simple and cheap so I can find parts anywhere. I might start with some Silverstars but will just replace with standard 2d1 lamps if I have to.

These are the housings I bought and they came with 2d1 GE lamps so I will get to see how they work then decide if I need to go to special bulbs.

 

[bugwhacker]

Question/advice needed. New rear end with disc brakes.

With my junkyard van purchase I negotiated a new rear end complete into the deal as I knew I wanted to go to disc brakes. I know the 1999 and newer vans came with disc brakes and should fit but I don't know if its 1999 until present or if there is a cut-off year. I haven't decided on a ratio yet but I think 3.73 should be a good compromise with my 7.3 IDI - E4OD - 265/75-16 combination. My objective is get the best mpg I can at 55 mpg as I honestly don't see driving that fast too often south of the border.

1.) What years are the best fit for my 1991 e350 to get disc brakes.
2.) Is 3.73 the right gear or should I think about a 3.54?
3.) The D60FF with locker is readily available to me in 3.73 or 3.54 but I might be able able to get a D70FF out of a SRW E450 but they all came with a 4.10 from the factory as far as I can tell. Do I really need the D70?

 

[Mwilliamshs]

Glad you asked about modern axle swaps for disc brakes as I'm looking to do that too!
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7.3 IDI likes about 1800-2000 cruise rpm in M/T applications but with the E4OD I'd do some driving/testing to determine where your TC lockup occurs and aim for that. Find what RPM it happens at now (can do MPH math since likely no tach) and try to hit that RPM below your intended cruise MPH. OR, and this is what I'd probably do, have manual lockup control.
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3.54, 31.8" (265/75-16 BFG A/T), 0.71 (E4OD OD), 55 mph = 1,461 RPM. Too low. Means you'll be in 3rd gear till 75ish (2000 rpm)
.
3.73, 31.8" (265/75-16 BFG A/T), 0.71 (E4OD OD), 55 mph = 1,540 RPM. Too low. Means you'll be in 3rd gear till 70ish (2000 rpm)
.
4.10, 31.8" (265/75-16 BFG A/T), 0.71 (E4OD OD), 55 mph = 1,692 RPM. Too low. Means you'll be in 3rd gear till 65ish (2000 rpm)
.
4.56, 31.8" (265/75-16 BFG A/T), 0.71 (E4OD OD), 55 mph = 1,882 RPM. Not bad. Means you'll be in 3rd gear till 58ish (2000 rpm) but then should be able to ease off the pedal and get lockup and cruise at 55-60 mph in OD without constant downshifting for small hills, pedal movement, etc. Hauling a camper's weight and having a high road-load with that tall roof line and AT tires should make this basically ideal since even 70 mph is still under 2,400 RPM. That'll make getting a run at big climbs and the occasional high-speed backtrack (missed turns, etc) real easy.
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I'm in a similar boat with taking a 3rd Gen E-van on a PanAm trip. Stock is 3.08 gears with my C6 and 29" tires. I've also aimed at about a 55-60 highway speed. Road conditions coupled with the fact I'm going on the trip to see things not get places mean I'm not gonna try for 70 at all. My plan is to end up with my torquey 300 straight six at about 2200 rpm at 55 mph with 3.55s which means 30" tires. The shorter tires allow for easier gearing and less air under the van for better MPG. Ground clearance is obviously not my primary objective. If I do go to a D60 I'll probably go up in tire size to offset the deeper gearing and the bigger centersection since a 30" tire and that big pumpkin would make even just crossing a curb iffy. Hoping that when the time comes I stumble upon a disc braked, 3.55, Dana 60 and some 17x7" wheels to run 245/75-17s on, 31.6" tall.
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I would not bother with the Dana 70 unless it falls in your lap cheaper or easier than the Dana 60. With single rear tires (vs DRW) you'll find the 60 more easily since most D70s are narrowed for dual rear wheels and no way you'll overload a D70 before you overload the tires anyway, since the Load E in your size are only good for about 6,900 lbs and the Dana 60 FF has a GAWR of 6,500.

 

[Bikersmurf]

As for an alternator I am replacing mine with a standard 130 amp big frame 3G alternator from a ford Taurus. I would love to run duel alternators but it doesnt seem like anyone has figured out how to do that on the IDI v-belt setups without giving up AC which is not an option for me. I am trying to keep things simple and cheap so I can find parts anywhere. I might start with some Silverstars but will just replace with standard 2d1 lamps if I have to.

These are the housings I bought and they came with 2d1 GE lamps so I will get to see how they work then decide if I need to go to special bulbs.

View attachment 272167

View attachment 272168

The 215 Amp Mitsubishi alternator is stock on 7.3 PSD Ambulances, and will fit other 7.3s from what I understand... It'll put out full power all day long if needed. There's no need to go dual alternators.

 

[bugwhacker]

That alternator is a serpentine belt direct bolt model, I would have to rig a bracket to make it an ear type as that is how the belt is tightened on a v-belt setup.

 

[bugwhacker]

I forgot to mention that my plan was to use the "OD Off" button and run in 3rd gear direct most of the time unless I wanted to run fast up in the States or when in Low range to give me a little more on my top end for mountain climbing at slow speed like happens all the time when you get stuck behind someone down there. I have also looked into some of the aftermarket e4od controllers and it looks like I could set one up for different personalities.

1 = pokey fuel saver mode that never shifts into 4th but tries to keep you in your power band of the IDI even though acceleration will be affected.
2 = time to run on the highway lets do 70.
3 = in gear reduction mode use all 4 gears but be careful of the shifts so you don't break stuff.
4 = pulling a trailer.

Glad you asked about modern axle swaps for disc brakes as I'm looking to do that too!
.
7.3 IDI likes about 1800-2000 cruise rpm in M/T applications but with the E4OD I'd do some driving/testing to determine where your TC lockup occurs and aim for that. Find what RPM it happens at now (can do MPH math since likely no tach) and try to hit that RPM below your intended cruise MPH. OR, and this is what I'd probably do, have manual lockup control.
.
3.54, 31.8" (265/75-16 BFG A/T), 0.71 (E4OD OD), 55 mph = 1,461 RPM. Too low. Means you'll be in 3rd gear till 75ish (2000 rpm)
.
3.73, 31.8" (265/75-16 BFG A/T), 0.71 (E4OD OD), 55 mph = 1,540 RPM. Too low. Means you'll be in 3rd gear till 70ish (2000 rpm)
.
4.10, 31.8" (265/75-16 BFG A/T), 0.71 (E4OD OD), 55 mph = 1,692 RPM. Too low. Means you'll be in 3rd gear till 65ish (2000 rpm)
.
4.56, 31.8" (265/75-16 BFG A/T), 0.71 (E4OD OD), 55 mph = 1,882 RPM. Not bad. Means you'll be in 3rd gear till 58ish (2000 rpm) but then should be able to ease off the pedal and get lockup and cruise at 55-60 mph in OD without constant downshifting for small hills, pedal movement, etc. Hauling a camper's weight and having a high road-load with that tall roof line and AT tires should make this basically ideal since even 70 mph is still under 2,400 RPM. That'll make getting a run at big climbs and the occasional high-speed backtrack (missed turns, etc) real easy.
.
I'm in a similar boat with taking a 3rd Gen E-van on a PanAm trip. Stock is 3.08 gears with my C6 and 29" tires. I've also aimed at about a 55-60 highway speed. Road conditions coupled with the fact I'm going on the trip to see things not get places mean I'm not gonna try for 70 at all. My plan is to end up with my torquey 300 straight six at about 2200 rpm at 55 mph with 3.55s which means 30" tires. The shorter tires allow for easier gearing and less air under the van for better MPG. Ground clearance is obviously not my primary objective. If I do go to a D60 I'll probably go up in tire size to offset the deeper gearing and the bigger centersection since a 30" tire and that big pumpkin would make even just crossing a curb iffy. Hoping that when the time comes I stumble upon a disc braked, 3.55, Dana 60 and some 17x7" wheels to run 245/75-17s on, 31.6" tall.
.
I would not bother with the Dana 70 unless it falls in your lap cheaper or easier than the Dana 60. With single rear tires (vs DRW) you'll find the 60 more easily since most D70s are narrowed for dual rear wheels and no way you'll overload a D70 before you overload the tires anyway, since the Load E in your size are only good for about 6,900 lbs and the Dana 60 FF has a GAWR of 6,500.

 

[Mwilliamshs]

I forgot to mention that my plan was to use the "OD Off" button and run in 3rd gear direct most of the time unless I wanted to run fast up in the States or when in Low range to give me a little more on my top end for mountain climbing at slow speed like happens all the time when you get stuck behind someone down there...

Interesting. So long as the TC is locked (manual mod or Aftermarket controller) that should work about as well. Still less efficient on a rpm:miles scale though. BFG specs those 265/75-16 ATs at 654 revs per mile. 654 w/ 3.54s @ 1:1 (3rd gear, TC locked) requires 2244.36 engine revolutions to travel one mile, at any speed. Same combo, but in O/D requires 1593.49 engine revolutions per mile. I'm not saying ~700 revolutions is a BIG deal, but gearing correctly to use OD will save 17,500,000 engine revolutions over a 25,000 mile stretch of highway. Say only 25% of my ~25,000 mile PanAm trip is at speeds appropriate for OD, that's still 4,375,000 engine revolutions, the same as about 85 hours (3.5 days) at idle. Again, not the biggest thing in the world but still, if you're changing gears and whatnot might as well get as much gain from the changes as you can.
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...when in Low range to give me a little more on my top end for mountain climbing at slow speed like happens all the time when you get stuck behind someone down there...

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Can't say I've ever been very closely behind someone where I'd be in 4 wheel drive and low range. Using OD in 4low could also create a lot of heat at speeds where airflow to get rid of it would be limited and that's a lot of shifting to get from 1 to 4 not to mention the drastic reduction in engine braking in higher trans gears with an automatic on the kind of terrain (where you'd use 4low) where engine braking can be so useful. Could overcome that with the TC lockup but again, heat and strain.
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I'm sure your strategy will work for you and if I had an E4OD instead of my C6 I'd have to make the same decision. I sought out the combo I have (300ci, C6) as I'm sure you pursued your drivetrain. Excited by such a similar rig with similar goals being built here and look forward to your posts! My build thread (very slow and quite wordy with too few pics) is over in the sportsmobile section if you'd like to take a look. I assure you it's not great reading lol.

 

[bugwhacker]

I won't be in 4 wheel low going up mountains if I can help it. I am twin sticking my np205 so I can run in 2wd low. Its an easy Mod that allows you to run your transfer case any way you want to. I am hoping that front locking hubs with an ARB air locker shoved in the front and a LSD in the back will help with my MPG some by allowing me to unlock everything and just run in 2wd with no extra drivetrain losses from the 4wd equipment. Also with this setup if you had to you could run on FWD only if you broke something in your rear end.

 

[bugwhacker]

Brakes

I am looking at getting my new rear axle soon and started thinking about the brakes and what needs to be done get them working as well as possible. I am getting a 1999+ d60FF from a van with disc brakes for my swap and I have d44 front from my pathfinder converted van.

The biggest rotor that can be fit into a 16" wheel like I will be using is 13" and that is what is on the front of a 1999 E350, the d44 front from the Pathfinder uses an 8 bolt spindle and hub assembly with either a 12.50" (chevy) or 12.56" (ford) rotor depending on who you ask and what years it was put together. I looked and cannot find a 13" rotor for a 4x4 application that will fit either of those spindles so I guess I am stuck with that but it is really close. The rear rotor of the 1999+ E350 is 12.83".

1999 E350 front rotor

1977 Chevy front rotor

1977 Ford front rotor

1999 E350 FF rear rotor

The next thing to look at is the Caliper.
The 1999 E350 unit is a twin piston floating caliper that has a (2.20") bore, = 15.2" squared of applied area.
The 1977 chevy is a single piston floating caliper that has a 75mm (2.95") bore, = 13.66" squared of applied area.
The 1977 ford is a twin piston floating caliper with a 56mm (2.20") bore, 15.2" squared of applied area.
There is an aftermarket upgrade caliper for the chevy called the "D52" from Wilwood that is a twin piston floating caliper with a 50.8mm (2") bore, 12.56" squared of applied area.

So the best match is the 1977 ford caliper then a toss-up between the chevy or the Wilwood, I say toss-up because twin pistons generally apply the pads more evenly then single pistons do but they are almost an inch smaller in applied area which is a huge amount. If I had the chevy calipers I would change my wheel ends over the the ford units if I could. Luckily I have the ford ends on my Pathfinder conversion.

1999 E350 front caliper

1977 ford front caliper

1977 chevy front caliper

Wilwood D52 caliper

The 1999 E350 rear caliper is 44mm (1.73") bore, = 9.4" squared of applied area.

1999 E350 rear caliper

Since the front of my Pathfinder 4x4 axle has the same caliper size and configuration as the 1999 donor E350 van my rear axle will come from, my brake bias will stay pretty close to the 1999 E350 if I change to a master cylinder of the 1999 E350 size/type which was my plan anyway with a switch from disc/drums to disc/disc. The only real difference will be my slightly smaller rotor on the front.

Next will be system pressure. The 1999 vans had pretty good brakes but being heavily loaded as an RV will push them to their limits so it is time for more power in the way of a hydra-boost conversion.

This subject has been covered a thousand times with parts coming from a lot of different vehicles to make it work. I am going the junkyard route as a new hydra-boost unit is rather spendy. I have the 7.3 IDI which come with the Saginaw pump already so I wont need to worry about how to mount the pump but will need to source one with 2 return lines. I plan to get my Hydra-boost unit from a Astrovan as they are really plentiful in the local yards and they are supposed to be an easy install? I wish I could find a nice step by step install in van of my era with a 7.3

 

[Mwilliamshs]

...Also with this setup if you had to you could run on FWD only if you broke something in your rear end.

Can do that anyway unless you have a slip yoke on your transfer case rear output and break the driveshaft (in which case the fluid runs out) but I've even run a jeep with a slip-yoke by capping the rear with a 20oz mtn dew bottle and some duct tape then drove about 100 miles on the front axle in 4hi. We broke the rear driveshaft. If we'd broken something else like an axleshaft, no mod necessary just drive home in 4hi. That puts a lot of stress on the front axle but there's no reason any transfer case can't do it unless weakness is an issue and with a NP205, it ain't...not that I know of a NP205 with a slip yoke anyway just saying no special case or modifications required to use FWD only. Depending on what broke, just pull the driveshaft if you have to, which with the rear end broken, is gonna have to happen anyway most likely.

 

[Mwilliamshs]

I won't be in 4 wheel low going up mountains if I can help it. I am twin sticking my np205 so I can run in 2wd low...front locking hubs...

Can do this without transfer case mods too. Shift into 4lo but don't lock the hubs and you'll be in 2lo. Done this a lot spotting campers and launching boats.

If you want to twin stick it, go for it but for the reasons you've named I'd skip it. An extra shifter in the floor is just in the way in a van you'll be in for months or a small rig like a jeep. I had an M38A1 with t90, OE twin-sticked Spicer 18, and a warn OD. that's 4 shifters plus a floor mounted parking brake between the seats. Neat conversation piece but it took forever to teach anyone to drive and had no room to get comfortable with that jungle-gym between the seats.

 

[Mwilliamshs]

How's that 99 E-350 D60 FF match up for WMS-WMS and spring perches? Very interested in this!