SRW 450 Mountain Build

cph05a

New member
Hi everyone!

I haven't posted much on EP yet, but I'm hoping to change that with a new build I just started on!

A little background... I've been driving around the mountains in a 1995 northstar pop up on a 2001 silverado 1500 for quite some time now. I've driven it through deep snow (most of the time successfully), up rough roads in the mountains. It'll be sad to see it go, but it's really showing it's age and it's time to build something new from the ground up!
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My Silverado is still running great, but the camper's roof is falling apart. Surprisingly it doesn't leak even though it looks like it should. With the amount of time I've spent in this thing, I want something with a little more living space and for that I need a bigger truck. I've been sharing this space with my Fiance, a husky and a cat so space is definitely tight.


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For the new build, I've got a 2007 F-450 SuperCab with 4WD which I'll be converting to SRW. It's got a flatbed on there now, but I'm planning to remove the flatbed and have a custom chassis-mounted pop up camper built on it. I've got big plans for this thing! My goal with this thing is to be able drive through snowstorms and drive on some mild to moderate off road trails in the summer so that I can get to my climbing/mountaineering/splitboarding objectives. I don't need to do any intense rock crawling, but I don't want pavement to be a requirement either. It has a 162" wheelbase so it's gonna be big, but not too crazy. In fact, it has pretty close to the same turning radius as my 143" wheelbase silverado. I'm thinking that with a little bit of a lift and 41" tire I'll be able to get around just fine.

I'm having the camper built by Phoneix Pop Up. It'll be 90in wide with a floor length of 10ft long (for reference, the flatbed on there now is 9ft) and a front to back sleeper over the cab. I'm planning to have a passthrough between the truck and the camper, 600W of solar power on the roof and a 6kWhr battery system to go along with it. I'm replacing the stock wheels and tires with 41" mpt 81 tires although I might end up changing these to the G275 MSA at some point.

Here is a rough sketch of the floor plan I'm hoping for. It says 88" wide, but I've been talking to Phoenix about expanding this to 90" since the SRW conversion is going to be a bit wider than I initially thought. My floor plan has changed a lot since the first few times I sketched it out, but so far I've ended up with this one.
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I'm on a wait list for the camper build but my turn is coming up soon so hopefully we'll see this thing become a reality! The front to back sleeping bed in my sketch is cut off. A few features I'm planning to pack into this thing include:
  • 15gal fresh water tank
  • 40gal separate shower water tank. I plan to capture grey water and reuse it for showering with a whole house filter and a UV sterilizer so keeping the two tanks separate is a must!
  • 3 burner rangetop stove with an oven running on propane
  • 130L Isotherm Cruise Fridge running on 12V
  • 20kBTU forced air heater running on propane
  • 500W Wall mounted air-conditioning unit
  • 2 grill sized propane tanks
  • electric lift system and snow braces
  • insulated pop up material with velco on the inside to add another layer of reflectix insulation for when it's below 0F.
  • pass through into the back seat of the truck
  • bathroom/shower that folds down into a counter top
  • toilet that doesn't require blackwater
  • skylight
  • storage underneath and along either side of the bed
  • RVS camera system to render an overhead view of my surroundings when I try to park
  • Removable spare tire mount on the back.
The 40gal shower tank won't be used in the winter, but the 15gal water tank will be fully enclosed in the interior to keep it from freezing. I also plan to repaint the truck to match the camper. It needs a little body work anyway.

For now, I'm working with Dusty Dog Garage in Englewood, Colorado to do the SRW conversion. I managed to get a used set of DBL Design wheels for this in 20x10 with double beadlocks. They are DOT legal and they come with a set of MPT-81s in 335/80r20.
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It'll be a bit more challenging to get the 41" MPT-81s to fit on the 2007 F450 compared to some of the newer models, but we're gonna try a 2.5" lift with fender flare cut outs and stabilizer kit and see we can fit it under there and if not we'll go up another inch or two as needed. Since I'm not towing anything I'm gonna keep the stock gearing ratio and see how it does before changing it.

One of the big challenges that I haven't quite figured out yet is how to get the engine and oil warm before staring in the winter. I've camped in my current set up down to -20F a few times every year since I got it and it'll be a bit different in the 6.0L Powerstroke. It's got an electric 1000W engine block heater in there now that works, but I'm thinking about replacing it with either a diesel or propane powered block heater and maybe adding an oil pan heater powered from my camper battery, but I haven't entirely decided yet. I've never had it fail to to start, but I really don't want to be starting it cold at that temperature ever if I can help it. The engine is in great condition and I want to keep it that way. I'm thinking if I can run the block heater on diesel or propane all night and then run the oil pan heater for an hour or so in the morning I shouldn't have a problem. Has anyone tried this?

Another thing I still have to figure out is what I'm going to do about vehicle recovery. I try to stay within the limits of my vehicle whenever I can, but I have gotten my Silverado stuck in the snow a couple times. My best guess is that the final weight of the build is going to be something like 10,000 - 11000lbs so a high lift jack won't cut it. I probably need a winch. I do have a hydraulic jack that goes up to 20,000lbs but I'm not 100% sure it'll be tall enough once my new tires and lift are on there.

I'm hoping I can "finish" thing by the end of the summer or maybe early fall and I'll be posting updates along the way!
 
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Superduty

Adventurer
41" is a lot of tire for no gear ratio change. It's gonna be a beast. If you do end up doing gears install lockers front and rear and the odds of getting stuck decrease dramatically.
 

cph05a

New member
41" is a lot of tire for no gear ratio change. It's gonna be a beast. If you do end up doing gears install lockers front and rear and the odds of getting stuck decrease dramatically.
Yeah it's a pretty big change from the 31s that are on there now. We'll see. I might end up going up to 4.88 or 5.38. Lockers on the front might be in my future either way but I'm not sure I can do anything other than a limited slip on the rear.
 

heimbig

OnTheRoadAtLast
The tire upgrade will put extra stress on brakes all around and everything that moves in the front end. There are good after market replacements for ball joints and the unit bearings - do that as part of your tire upgrade. Also consider upgading the power steering pump (maybe replace stock hydrostatic with a solid hydraulic ram) and increase the size of the reservoir.
Don't let the naysayers change your mind on Phoenix I have one and l'm now in Mali Africa with mine. BUT DO make sure he builds what you want.
Unless you are an engineer with years of success with swivel camper mount don't do it.
 

RPhil

Adventurer
Solid platform to start with, I believe you should have the Dana Super 60 front axle. What gears do you currently have? I thought the F450 may have had 4.88's from the factory. I don't think you will have a problem fitting your tires with your plan, worst case scenario you may need to push the axle forward and/or trim. I am following along, I think a 2005-2010 F450 is an ideal candidate for the type of camper you are building, which I would love to do one day.

Any plans to "bulletproof" the engine?

One option for engine preheat is an Espar coolant heater. If you want, you could reconsider your propane heater and look into radiant heat systems. The Espar could be used to heat the camper and/or the engine coolant loop depending on how everything is plumbed. There are quite a few examples within this forum.
 

cph05a

New member
heimbig, I had the ball joins and bearings replaced when got the truck since the old ones were broken. They're less than 6 months old so they should be good to go.

Does your 550 build have a pivot frame on it? I'm curious what problems there have been with the phoenix installed pivot frames. In theory it sounds like a good thing... but only if it works as intended and doesn't break all the time.

RPhil, some F450s came with 4.88s, but mine has 4.30s on it now. I've gone back and forth on whether or not to bullletproof the engine. Initially I think I'm going to leave it as is just because it might be out of the budget at the moment, but I haven't completely ruled it out yet. The espar heater looks really promising as a preheating solution! There's also a propane one I might be interested in, but I'm not sure how hard/advisable it would be to run a propane line from the camper to the engine block. I've kind of liked the idea of keeping the living area fuel separate from the driving fuel so that I don't run the heater too much and get stuck, but then again the 450 has 40gal tank.
 

java

Expedition Leader
Your going to want to regear. I have 4.30's and my 35's feel ok, but wouldn't want to go bigger

Bulletproof it, it's kinda required on the 6.0's IMO. My 6.4 has never had issues starting in the cold.

Great build!



Sent from my SM-G950U using Tapatalk
 

RPhil

Adventurer
...

RPhil, some F450s came with 4.88s, but mine has 4.30s on it now. I've gone back and forth on whether or not to bullletproof the engine. Initially I think I'm going to leave it as is just because it might be out of the budget at the moment, but I haven't completely ruled it out yet. The espar heater looks really promising as a preheating solution! There's also a propane one I might be interested in, but I'm not sure how hard/advisable it would be to run a propane line from the camper to the engine block. I've kind of liked the idea of keeping the living area fuel separate from the driving fuel so that I don't run the heater too much and get stuck, but then again the 450 has 40gal tank.
If you find a completed 4.88 front axle to swap in, I’ll take the 4.30 off your hands to throw under my Excursion, seems like a good excuse to get around to my coil spring swap ;)

Good luck with everything, I will be following along.
 

heimbig

OnTheRoadAtLast
heimbig, I had the ball joins and bearings replaced when got the truck since the old ones were broken. They're less than 6 months old so they should be good to go.

Does your 550 build have a pivot frame on it? I'm curious what problems there have been with the phoenix installed pivot frames. In theory it sounds like a good thing... but only if it works as intended and doesn't break all the time.
I had a local builder build a hinged bed using ford and Australian truck department of transportation (whatever they call it) reccomendations, not pivot frame and not phoenix (who I think subs this out) see build blog GOVE.

Pivot frames push your center of gravity up and frequent damage the vehicle or fail them selves.

I've also seen people build them claim they have the same frame flexibility and show photos that the truck frame does not flex. the lack of flex puts stress on your trucks frame.

The whole point of the pivot or floating bed is that the frame flexes as designed and the bed is rigid.

Also ford SPECIFICALLY recommends that the weight of the cargo be spread across the length of the truck frame this is VERY difficult to do with a pivot frame.

OH, take a look at the small cut out in your frame for the rear shocks. This is where the ford 550 frame has cracked for other people. STRONGLY recommend you bolt (NOT weld) a steel plate across this area (on the vertical side next to tire) using existing holes for reinforcement. The newest 4/550 (the series after my 2013 (~2017???) this notch is not there because dana moved the shock mount.
 
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cph05a

New member
I did a little bit of reading and I was really misusing the term pivot frame a bit :censored: I'm not planning to alter the frame of the truck at all. It's actually just has a pivot point in the rear between the truck and the camper frame. Nothing too crazy. I know the plan is for the attachments to the truck to be bolted and not welded. I'm trying to do anything too crazy and I calling it a pivot frame wasn't accurate on my part.

I found a picture of a similar attachment on an F-350:
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I think this similar to the plan for my build. It has a pivot point in the rear that allows the truck frame to move a little bit independently of the camper.
 

cph05a

New member
UPDATE Added power locks with aluminum door handles and we're half way through the SRW conversion.

I paid a visit to dusty dog garage for who is doing the SRW conversion. We did a little bit of articulation testing and when the truck is lifted by one of the rear wheels with the steering locked out it was rubbing just a little bit so we're going up one more inch so I don't have to limit the suspension travel to keep it from rubbing.

Here it is in progress. The fenders have been cut back to make room for the 41s. We'll be using bushwacker fender flares to replace the stock ones. In this picture, we've got the front up on a 3" lift and the rear is still stock. I need to get a new bumper on there but I'm not sure if it'll be done before or after the camper build just due to cost so I might be using the stock bumper trimmed back for a little bit. Still plenty of work to be done!
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cph05a

New member
Another update: The SRW conversion is finally complete! It ended up needing a 4.5" lift when it was all said and done and I'm pretty happy with the result. I do plan to get a new bumper for it, but the OEM one was trimmed to fit for now. It drives really well, especially considering it went from 31" tires to 41" tires. No codes on the computer and speedometer is accurate to within 1mph. Still running the 4.30 gears and it's driving well so far, but no camper on it yet.

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Huge thanks to Dusty Dog Garage for helping me with this project! Next up, the truck is heading to the body shop for some cosmetic repairs and then the camper build starts!
 
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