OBS F250/F350 Flatbed camper build

longroad2nowhere

Active member
Welp, just got home from a 2.5 week trip to Colorado, and this truck did not disappoint. Was slightly worried taking a 20+ year old truck out on such a big trip, but man did it handle it all. Drove up trails that reached almost 12k ft of elevation. Drove through temps up to 115 degrees. Tons of huge mountain passes. Off-roading. No problems. Our "overland" set-up was great too. It actually ended up being way more space than I expected. Two thumbs up for the James baroud tent as well. We slept great in it, and take about 30 seconds to open it, and a minute and a half to close. Really great tent. We are coming from fully built out sprinter van, and we really didnt miss some of the "luxuries" it had. It forced us to spend more time outside, and feel a bit more like we were actually camping again. It has made us really rethink our plans for a full-on camper build out. If we dont keep this set-up, we will probably make something more along the lines of go-fast camper, but for the flatbed. Something with a little more room and protection from the elements when the get bad, but not a full on "luxury" camper.

Here are some pictures from the trip. Lots more where that came from but I can only upload 10.
DSC06401.JPGDSC06407.JPGDSC06480.JPGDSC06488.JPGDSC06493.JPGDSC06546.JPGDSC06747.JPGDSC07054.JPGDSC07073.JPGDSC07338.JPG


All that said, I definitely want to do some more work to it. We went up some huge passes in CO, and it definitely felt a little bit underpowered, and the EGT's got a little higher than I hoped. I did not get my hydra chip installed before we left cause it showed up the day before we left, and I didnt want to install without being able to drive around with it for a bit before we left. Assume that will help a lot with the uphill power. I have a downpipe to install, but kind of thinking I should just do a full 4" exhaust. That plus an intercooler (prob my next purchase) should help with the egt's. That said egt's were pretty manageable as long as I kept the rev's up. It would just be nice to keep them lower and not have to worry about turning off overdrive or putting it into 2nd so often. As for off-roading, this thing impressed me. Climbs like a mountain goat. Just go slow and she climbs right up everything. Did find out that I had a bit of tire rub on the front fender when going downhill and turning off-road, so I'll have to do a bit trimming on the fender. Also, A+ for these nitto ridge grappler tires. They are pretty damn quite on road, and work great off-road.

Coming projects to hopefully get done in the next month or so.

Chip install
exhaust
rear disc brake conversion
intercooler
drop down fridge slide
rear underbed tool boxes to match the front.

I am loving this truck and cant wait to keep making it better and better.
 

IdaSHO

IDACAMPER
The big rubber and taller final ration is certainly working against you with regards to EGTs
These motors like revs to keep the EGTs down.

Unless you plan on re-gearing, intercooler and a conservative tune should do it.

Having an OBS 7.3 myself, it always amazes me that so many people seem to tow REAL heavy with them without melt-down.
I can peg the EGT gauge pretty easily, even when 100% stock. Perhaps they really are that tough (y)
 

drumguy_18

New member
A chip & exhaust will help EGTs immediately. Intercooler will help even more. You’ll love your next road trip with the truck.
 

glock7018

Member
I would defiantly do a full 4 inch exhaust. They just sound so mean. Nothing sounds better than a straight piped OBS 7.3. Inter cooler is defiantly going to be needed. The only kit i would recommend is the Banks kit. I know 1500 is kind of a a lot to swallow. But its a complete kit meant for old fudds to install.
 

longroad2nowhere

Active member
The big rubber and taller final ration is certainly working against you with regards to EGTs
These motors like revs to keep the EGTs down.

Unless you plan on re-gearing, intercooler and a conservative tune should do it.

Having an OBS 7.3 myself, it always amazes me that so many people seem to tow REAL heavy with them without melt-down.
I can peg the EGT gauge pretty easily, even when 100% stock. Perhaps they really are that tough (y)


Yea I was amazed how many obs trucks i saw pulling giant trailers or boats on this trip. Maybe ignorance is really bliss in this case. Just let it do its thing dont install an egt gauge, and hope for the best. They must be pretty damn tough.
 

longroad2nowhere

Active member
Did your lady fall out of the tent? (First pic)

hahah. No, first morning of the trip and we camped in the AZ desert and it was already near 100 degrees when we woke up. She just got out of the tent and found the only shade.

I would defiantly do a full 4 inch exhaust. They just sound so mean. Nothing sounds better than a straight piped OBS 7.3. Inter cooler is defiantly going to be needed. The only kit i would recommend is the Banks kit. I know 1500 is kind of a a lot to swallow. But its a complete kit meant for old fudds to install.

Just ordered a 4" ss diamond eye. Opted for a muffler so my neighbors dont hate me as much. CP addict sells another complete intercooler kit that seems pretty bolt on, for much less than the banks. one review said lots of mods needed to install, but the other two said easy install. no problems. Maybe its worth paying for the banks to make sure. We'll see.
 

glock7018

Member
hahah. No, first morning of the trip and we camped in the AZ desert and it was already near 100 degrees when we woke up. She just got out of the tent and found the only shade.



Just ordered a 4" ss diamond eye. Opted for a muffler so my neighbors dont hate me as much. CP addict sells another complete intercooler kit that seems pretty bolt on, for much less than the banks. one review said lots of mods needed to install, but the other two said easy install. no problems. Maybe its worth paying for the banks to make sure. We'll see.

I have seen that kit too. The main think I dont like about it the cheesy mount that bolts the inter cooler to the hood latch. It being made out of aluminium I don't see it standing up to any sort of vibration/abuse.
 

longroad2nowhere

Active member
Hey guys, just been driving and (mostly) enjoying the truck, and kind of trying to decide what the next major move is. I installed the hydrachip and it definitely gave it some more power, but still dont love how it shifts. I live up in the mountains, and the traveling i do usually involves a lot of steep grade driving. I have the auto e40d trans, and it just doesnt downshift soon enough, or stay in a low gear long enough. If I wanna keep this truck for a long time, i need to figure out something to do about this. Also one day while driving, something weird was happening with the transmission. Just wasnt shifting right. I babied it home, and ever since, its been fine, but not really confident driving it anywhere too far from home till i do something about it. Here are some options I'm weighing.

1) jwtt transmission. exhaust. intercooler. This will give me basically the best option available for an auto trans. Exhaust and intercooler will give me a bit more power and keep the egt's down, and hopefully the extra power will help the limits of the 4 speed and its shifting points.

2) swap in a zf5. exhaust and intercooler again. Being able to control the shifting myself should help some of my problems. Downfalls, i'm not capable of doing this job myself, there are apparently lots of little bits and pieces to track down, and I feel like it will end up costing me a decent chunk of change, which if I'm going to really spend some cash, should I do my dream project...

3) cummins 12v swap and either a zf5 or nv4500 trans. Cummins swap is kinda the dream set-up for this truck. Not cheap, but if I take the time to find the right motor and trans at the right price, it may end up being worth it? Part of me feels silly pulling out my 7.3 that is running great, but man a 12v would be cool to have in there.

Would love to hear some opinions. Like I said, if I wanna keep this truck, which i do, I gotta figure out how to make it a bit more enjoyable to drive up mountain passes. Would love to hear some opinions from obs and 12v owners.
 

UHAULER

Explorer
I don't really have an answer for you but that is the one thing I didn't like about my 02 f350 with the 7.3 and 4r100. It just seemed to never be in the right gear in the mountains. Too bad they didn't have a 5r110 behind a 7.3.
My buddy has a 2000 f350, 7.3 with a zf6. Much better in the mountains. If my truck had a 6 speed I would have kept it.
If you really want to keep the truck, a 5 or 6 speed would be the way to go or if you can , do it with the 5.9.
 
I don't really have an answer for you but that is the one thing I didn't like about my 02 f350 with the 7.3 and 4r100. It just seemed to never be in the right gear in the mountains. Too bad they didn't have a 5r110 behind a 7.3.
My buddy has a 2000 f350, 7.3 with a zf6. Much better in the mountains. If my truck had a 6 speed I would have kept it.
If you really want to keep the truck, a 5 or 6 speed would be the way to go or if you can , do it with the 5.9.


I had a 99 F350 7.3 with the ZF6. It was a serious puller in the mountains. Frequently towed my 6000 lb deck boat up to Big Bear California during the summer. Typically, everyone behind is acting all crazy to pass you before the grade begins. One day, I had a guy riding my bumper in a Yukon. Normally, I would always let everyone by, but this guy was really aggressive. So, I decided to just keep going, and put the pedal to the metal. For a while, he was able to keep up, but didn't have enough juice to pass me. About half way up, he was beginning to lose ground. By the top, he was a half mile behind. A turbo diesel can really do the job at altitude. That was one sweet truck...
 

chet6.7

Explorer
3) cummins 12v swap and either a zf5 or nv4500 trans. Cummins swap is kinda the dream set-up for this truck. Not cheap, but if I take the time to find the right motor and trans at the right price, it may end up being worth it? Part of me feels silly pulling out my 7.3 that is running great, but man a 12v would be cool to have in there.
I had a 4500HD in my 97 Ram,the first gear was not as low as the SM465 first gear,I missed that.There were some problems with the 5th gear as I remember it,I didn't have any, but I didn't lug it or tow heavy.I did like that it was an all synchromesh trans,it shifted into 1st and reverse much better then the SM465.I think a six speed would be a better choice.
I like your rig.
 

glock7018

Member
A built transmission and good tunes will help your shifting. Just keep in mind the E4OD is a very basic trans. I have a built trans and a tunes from jelibilt and I got it dialed in. It may take a few revisions to get it dialed in right. You will probably just have to keep it locked out of OD in the hills. Which is something I have had to do on every auto truck I have had. Everything from a 4 speed, 5 speed, and 6 speed.

For the cost and time of a manual swap you could have a overbuilt auto trans put in. And a 12V swap is just silly when there is nothing wrong with the original 7.3.

Also more power will help alot. I got 180CC 30% injectors, 17* Hpop, up pipes, and a bigger turbo. With 4.10 gears and 35's I know longer have to rely on downshifting for more power when it comes to passing. . I just ease into the fuel and it takes off like a rocket in 4th.
 

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