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F350 to F550 conversion

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32K views 11 replies 6 participants last post by  artherd  
#1 ·
What (besides the D135 rear axle of course) does it take to turn an early '99 F350 into an early '99(ish) F550?

I don't really want to buy a new truck, good clean cheap XLT or better 01-02 4x4 F550s are HARD to find.

But I will need the increased payload/weight capacity. (installing a 1500lb service body, plus 500lbs of lift-gate, leaves exactly 0 lbs of payload on a one-ton /ubbthreads/images/graemlins/smile.gif

The Plan:
1) Swap in a D135 (converted to 4.10 or 3.73 ratio.) and 19.5" alcoa wheels, have a driveline shop weld new spring perches a few more inches out.
2) Install auto-leveling airbags (or full air-ride if it will fit a pickup frame width) to give the extra sprung carrying capacity.
3) bolt on F550 front wheel adapters and 19.5" alcoa wheels.
4) optionally install front F550 calipers and rotors, do they bolt up to the F350?

I know the pickup frame is wider than the chassis cab frame, and I know the front F550 wheel adapters will bolt on.

What else differs? Specifically how about the front hubs for caliper/rotor attachment? My front D60 is rated at 6000lbs, same as an F550's D60, but are they the same?

How about rear axle widths? Are they different?
 
#2 ·
if you are interested, i have a complete front axle and suspension with wheels out of a 2wd 450. i would think it is the same as a 550. the truck it came out of had a fire, so brake lines and abs wires would need to be replaced. it also has tires, but they are about bald anyway and have plastic melted onto them from the inner fender liners. i can try to get some pics this week if you are interested.
 
#4 ·
The FRAME is different (from the 350 chassis cabs)? This is the first I have heard of that. Can anyone ellaborate?
 
#7 ·
Is it any stronger?
 
#8 ·
Besides all this, nothing you can swap onto this truck will provide you with a official payload increase. You will still have a truck that can legally only carry what it used to.
 
#9 ·
[ QUOTE ]
Besides all this, nothing you can swap onto this truck will provide you with a official payload increase. You will still have a truck that can legally only carry what it used to.

[/ QUOTE ]

Wrong, DOT can and does recertify trucks with upgrades for higher weight ratings (mainly for tax purposes)
 
#10 ·
In CA I could classify my 350 to carry 40,000lbs (doesn't mean it's prudent /ubbthreads/images/graemlins/smile.gif

What I am looking for is wether I should bother to upgrade, or just swap.
 
#12 ·
Thanks for pics, if it were a 4x4 axle I'd probally grab it, but don't need a 2x unfortunately.

I will have to move the spring perches out 2.1" each side, but it looks like it may be doable. (brake clearance could be an issue, still looking into it.)