1999 F450 4x4 Ambulance Toy Hauler

[Jds2835]

This is a build thread for my 1999 F450 4x4 Ambulance
7.3 Diesel, 78,000 miles
The build will serve as a family camper and toy hauler to camp in motorcycle enduro and mountain bike races. I've been slowly working on the build for around 9 months. I'm hoping this thread will give me some motivation to keep making progress.


I took me around 3 months to get all of the stickers off and the ambulances lights. I found clear covers for the red and blue lenses which really changed the look of the truck. This was from one of the first camping trips.



This biggest job so far was fitting 335/80/20 MPT 81 tires. I used surplus MRAP wheels and adapter plater from Western Canadian Rockwell. There is very little info on there on running this tire on the MRAP aluminum wheel. I had to learn a few things the hard way. The MRAP wheel is made for a larger tire with a 2" bead area and measure approximately 24" on the outside diameter. This causes the bead protection bump on the MPT 81 to contact the wheel lip and the tire doesn't fully seat on the bead the way it is designed to. I mounted 4 tires by hand before I figured this out. I hat the wheels cut down to 22.205" OD with and then cut an 11mm radius for the tire to seat against. I also removed the CTIS and installed Schrader valves on both sides of the aluminum wheel.






Here is how the truck currently looks. My next project is a spare tire mount, diesel heater and 6 speed manual transmission swap!

 

[Buddha.]

Did you have to modify the suspension to get the tires to fit? Do those bigger tires soften the ride? How does it do with stock gearing?

 

[Fatboyz]

I plan on possibly going the same route with tires. I have a 2001 F550. I live just down the road from WCR so adapters are easy. Are you in Canada? Our price on MRAP wheels with the adapters makes it almost the same as made to fit super singles from First Attack. Did you just have to do the cut out front fender flares to get the wheels to fit? Any other suspension mods?

 

[Jds2835]

Did you have to modify the suspension to get the tires to fit? Do those bigger tires soften the ride? How does it do with stock gearing?

The truck has rear air suspension so I increased the amount of air in the rear bags which raises it a few inches. I kept cutting material away until the tires fit. It was a lot of cutting. The front is bushwhacker cutout fender flares. The 41" tires on 20" wheels do ride softer compared to the stock 31" tires on 19.5" wheels there is more sidewall flex. It has 4.88 gears which are super low with stock tires. The 41" tires let me cruise around 1900 rpm on the highway which is where the 7.3 diesel is happy. It does feel underpowered but the engine is all stock and pretty restricted. I plan to do some power upgrades down the road.

 

[Jds2835]

I plan on possibly going the same route with tires. I have a 2001 F550. I live just down the road from WCR so adapters are easy. Are you in Canada? Our price on MRAP wheels with the adapters makes it almost the same as made to fit super singles from First Attack. Did you just have to do the cut out front fender flares to get the wheels to fit? Any other suspension mods?

See if feltz tire will ship them to you https://feltztire.com/. They have the black MRAP wheels for $100 each. I wouldn't recommend the MRAP wheel for a 335 tire unless you have access to a machine shop that can cut the lip down. The MRAP wheels are made for 395 tires which have a bead area that is twice as big. Stazworks has MRAP wheels that are machined down to the correct size, setup for your bolt pattern and powdercoated for $550 each which is a fair price.

 

[Fatboyz]

My issue is I'm in Canada and MRAP wheels here are $550 each. Getting things shipped here from the US is crazy expensive.

 

[DirtWhiskey]

Thank you for posting this MRAP wheel cutting info. Might have just saved me some real heartache. Not sure why but most people who say "MRAP rims didn't work" don't really go into detail. I've seen a few 335 tires on MRAPS that seem to have a weird gap between the tire face and the outter ring of the rim. Oh well, Staz or 1st attack it is.

Do you have any issue with rubbing at full lock? Love that old 7.3 platform except for the front leafs. I'm looking at a rig from that era and possibly doing a 2005-2007 coil conversion. The way I understand it, you can cut the entire front frame clip of the newer truck at the service break in the frame behind the front axle, pop the rivets and it marries right up to the older frame. Gives you the wide track front and attendent AMAZING turning radius, better steering box and the 10 bolt hubs. I'm thinking I'd grab a donor rolling chassis for the operation to get the matching rear. IMHO Only drawback of the 7.3 platform is the radius/leaf and tranny, although you can get a fully built one from BTS that kicks butt. 7.3 is my favorite engine of all time. I've had three of them.

 

[OverlandFT]

JDS, the truck looks awesome on the new meats! It looks like the box fit the tires really well. Any idea what you'll do for the spare tire mount?

 

[Jds2835]

Do you have any issue with rubbing at full lock? Love that old 7.3 platform except for the front leafs. I'm looking at a rig from that era and possibly doing a 2005-2007 coil conversion. The way I understand it, you can cut the entire front frame clip of the newer truck at the service break in the frame behind the front axle, pop the rivets and it marries right up to the older frame. Gives you the wide track front and attendent AMAZING turning radius, better steering box and the 10 bolt hubs. I'm thinking I'd grab a donor rolling chassis for the operation to get the matching rear. IMHO Only drawback of the 7.3 platform is the radius/leaf and tranny, although you can get a fully built one from BTS that kicks butt. 7.3 is my favorite engine of all time. I've had three of them.
[/QUOTE]

The front tires hit the leaf springs by about 1/4" during a full lock turn. I wasn't going to be able to live with that so I drilled and tapped a hole in the steering stop on the steering knuckles. I put a 3/8"x16 bolt in the hole. This extended the steering stop by the thickness of the bolt head. It worked well was was easy to do. The turning radius isn't very good but it is a huge truck.

The drivetrain is all stock. I have a zf6 manual transmission waiting to be installed. I just got the manual transmission computer today. I'm slowly collecting parts for the swap. I need to get all of the clutch components and a different input shaft for the T case.

 

[Jds2835]

JDS, the truck looks awesome on the new meats! It looks like the box fit the tires really well. Any idea what you'll do for the spare tire mount?

Thanks! I did a lot of cutting to the rear fender area. The rear fender trim is fiberglass covered in a rubber molding. I cut the fiberglass fender into 4 pieces and stretched it out as far it would go to change the radius of the fender opening. I cut as high and wide as I could go on the aluminum body without cutting into the storage compartments.

I plan to make some type of swing out rear tire carrier where the tire sits on the rear bumper. I plan to have some type of ramp where I can roll it up onto the rear bumper like a shelf. The spare is laying on the floor inside the truck right now and it takes up a ton of space.

 

[1cambo]

This is a build thread for my 1999 F450 4x4 Ambulance
7.3 Diesel, 78,000 miles
The build will serve as a family camper and toy hauler to camp in motorcycle enduro and mountain bike races. I've been slowly working on the build for around 9 months. I'm hoping this thread will give me some motivation to keep making progress.

View attachment 625098
I took me around 3 months to get all of the stickers off and the ambulances lights. I found clear covers for the red and blue lenses which really changed the look of the truck. This was from one of the first camping trips.

View attachment 625099

This biggest job so far was fitting 335/80/20 MPT 81 tires. I used surplus MRAP wheels and adapter plater from Western Canadian Rockwell. There is very little info on there on running this tire on the MRAP aluminum wheel. I had to learn a few things the hard way. The MRAP wheel is made for a larger tire with a 2" bead area and measure approximately 24" on the outside diameter. This causes the bead protection bump on the MPT 81 to contact the wheel lip and the tire doesn't fully seat on the bead the way it is designed to. I mounted 4 tires by hand before I figured this out. I hat the wheels cut down to 22.205" OD with and then cut an 11mm radius for the tire to seat against. I also removed the CTIS and installed Schrader valves on both sides of the aluminum wheel.

View attachment 625100
View attachment 625101
View attachment 625102
View attachment 625103

Here is how the truck currently looks. My next project is a spare tire mount, diesel heater and 6 speed manual transmission swap!

View attachment 625104
View attachment 625105

Looks awesome!

 

[Jds2835]

Thanks! I did a lot of cutting to the rear fender area. The rear fender trim is fiberglass covered in a rubber molding. I cut the fiberglass fender into 4 pieces and stretched it out as far it would go to change the radius of the fender opening. I cut as high and wide as I could go on the aluminum body without cutting into the storage compartments.

I plan to make some type of swing out rear tire carrier where the tire sits on the rear bumper. I plan to have some type of ramp where I can roll it up onto the rear bumper like a shelf. The spare is laying on the floor inside the truck right now and it takes up a ton of space.

I finally got my tire carrier built this week. I’m happy with the result. I can roll the tire in out of the carrier without having to lift it.

 

[Jds2835]

 

[Jds2835]

 

[Jds2835]

Worked into the night to get it buttoned up. Added a spring loaded latch pin and bolt on ratchet strap.