lwb 5.8 4x4 swap?

[boywonder]

I drove my van with 4WD conversion 285/70-17's and 3.73 gearing for years......it got me where I was going. ....on long grades it would downshift out of OD and sometimes even down to second gear by the top of the grade. Speedo was off about 10% as well.

So I would do my best to get a good run before the grades up to maybe 75mph, and by the top 50-55 mph.

4.10's made a big difference on the long grades...it occasionally shifts out of OD but not often, and I don't feel like I need to be going 75-80 mph on the run up to the grade. Speedo off by a couple percent now.

Changing gearing isn't voodoo magic, I did both ends of my van, just watch a lot of youtubes and you'll need a few special tools. I sold everything (including my open carrier from my D60 front, replaced by an Eaton Tru-trac) after the swap. It's just a PITA and very tedious but by the 15th insertion of the carrier/ring gear you'll start to get the hang of it.

[posplayr]

Originally Posted by boywonder

I drove my van with 4WD conversion 285/70-17's and 3.73 gearing for years......it got me where I was going. ....on long grades it would downshift out of OD and sometimes even down to second gear by the top of the grade. Speedo was off about 10% as well.

So I would do my best to get a good run before the grades up to maybe 75mph, and by the top 50-55 mph.

4.10's made a big difference on the long grades...it occasionally shifts out of OD but not often, and I don't feel like I need to be going 75-80 mph on the run up to the grade. Speedo off by a couple percent now.

Changing gearing isn't voodoo magic, I did both ends of my van, just watch a lot of youtubes and you'll need a few special tools. I sold everything (including my open carrier from my D60 front, replaced by an Eaton Tru-trac) after the swap. It's just a PITA and very tedious but by the 15th insertion of the carrier/ring gear you'll start to get the hang of it.

These 3.73 2WD vans all seem to have 32 spline rear ends so I will have to go for the ARB if necessary and budget allowing. Of course, it would be much cheaper DIY. I have watched several videos and still come away not too enthused. Of course, if you were doing both front and back that would be a big motivator.

So am I to infer that a V-10 6.8L 2WD EB can't comfortably handle the 285/70-17 with 3.73s?

I'm pretty used to shifting out of OD on long grades as is. Especially down some long grades coming south on the 395 (south of Reno) ; it saves on the brakes.

Part of the apples and oranges is that the EB uses 245/75-16 vs the RB that are usually 225/75-16 so going 245/75-16 (30.49") -> 285/70-27 (32.71") is 1.073 or 7.3%.

The 6.8L has 425 ft-lbs of Torque vs 330 for the 5.4 (425/330) = 1.29 or 29% more.

As mentioned I'm much more likely to just drop down to 265's if the 285s' are too tall.

[86Scotty]

Originally Posted by posplayr

So am I to infer that a V-10 6.8L 2WD EB can't comfortably handle the 285/70-17 with 3.73s?

No, a V10 can handle 285's/3:73 just fine. Keep in mind that we are extreme cases around here, generally speaking. Sportsmobiles and campervans are generally loaded to the hilt and have all sorts of heavy and un-aerodynamic racks, etc. and also they are toys for most the majority of us. We modify them and try to make them quicker and stronger and spend money on them just because.

There are plenty of 5.4's pulling lots more weight in tougher conditions all over the nation and the world for that matter. The V10 is a very strong engine, regardless of gearing. No way I would bother changing gearing until you think you really need it, which may be never.

The tranny may hunt a little more after your tire change but it's fine if you can live with it. You might not mind it at all. Two cheaper and easier things you can do for any van is to use the tow/haul setting more and/or to spend $600 (half the cost of gearing) on a 5-star basic RV tune (SCT tuner).

Every time I start thinking my V10 needs a little more power I am reminded that it really doesn't by getting passed by a class C motorhome with some clueless citizen in it who is simply voting with their right foot. Apply throttle and RPM. The V10 is a beast of a motor with any gearing.

[posplayr]

Originally Posted by 86Scotty

No, a V10 can handle 285's/3:73 just fine.

Thanks, I pretty much knew this already but did not want to go to a lot of trouble cutting back my front fenders only to find I would rather have 265/70-17s vs the two sets of 285/70-17s I obtained for beer money.

I have not driven the van much, and it is big! So I'm glad you could answer my mild concerns.

[86Scotty]

Wait, was your question about clearance? I thought you were just talking about power and drivability. To be clear, I do not know what cutting, if any, would be necessary on a 2wd to fit 285's. I know it's been discussed though.

[posplayr]

Originally Posted by 86Scotty

Wait, was your question about clearance? I thought you were just talking about power and drivability. To be clear, I do not know what cutting, if any, would be necessary on a 2wd to fit 285's. I know it's been discussed though.

I had planned on putting 265/70-17 on my 17x8" wheels, but I found a Craigslist deal of 8 285/70-17 BFG KO2's for beer money (50% tread).

I know they are big for a 2WD Econoline but they are a standard size for a Ford Truck. A lot of the truck owners modify their front fenders in what they call "NorCal" mod. https://www.customwheeloffset.com/bl...-to-norcal-mod

Some do the mod to put on bigger tires without having to do the lift. That is fine for me. I'm mainly looking for more traction in case I pull off the road and get stuck in a little invisible sand. Back in 1995, I spent 8 hours digging my 1981 21ft motorhome out in Baja once. That is enough for me.

So I already practiced on my aforementioned 1997 E-350 (as it was totaled). I think I can get 2" of additional space on the back of the wheel and I have an Aluminess front bumper to refurbish

https://www.sportsmobileforum.com/fo...tml#post320999

Originally Posted by posplayr

I previously stated I thought I could get another 1/2" out of this mod, so I set about to see what was involved with cutting back the sheet metal box behind the pinch weld.

The bottom of this area is actually the furthest point forward at the back of the wheel well. So pushing it back (within reason) is the practical limiting factor for the maximum allowable Fender modification.

In summary, I was able to remove about 1 1/4" from this projecting box area. In order to realize this full amount of trimming you would have to remove an additional amount from the prior fender trim (1 1/4" by trimming the pinch weld and fender pie cut) which would be a total of 2 1/2".

The details are in a revised PowerPoint presentations.

https://www.dropbox.com/s/5fhkbgmgep...ldMod.pdf?dl=0

In the attached picture the reference is a 285/70-17 tire with 5" of lift. I plan to add about 2"in the rear with spacers and airbags 1.5-2" in the front with springs and spacers (but keeping the alignment under control) :

MOOG CC81366 Coil Spring Set

[batgirls]

You should visit https://timberlinesupply.com/

They have a lot of resources including a free build sheet. They spent ~10years converting vans in the shop in Golden Colorado. They got out of the build business this past year or so and now sell kits.

If you send them your VIN they can advise you on specifics for a windsor.

On fuel economy, our 92 e250 sportsmobile gets 13 on the highway at 75-80 mph. Stock wheels and tires (we haven’t converted to 4wd yet).

You may be better off paying the premium for a 4x4 van. Timberline builds start off around $18k.

Good luck with your adventures