Well.. The process of building a Factory Five car has begun. I'm not sure my wife understands what I'm trying to do (though she is incredibly tolerant of me and deserves a new piece of jewelry). My kids just think of this as a fun project.
I've attached a picture of my donor car. It's a 1999 Ford Explorer 5.0L. I bought it at a Copart auction for $350, excluding taxes and fees. I have a daily commute of about 40 miles total each day. So my plan was to drive it for the next 6 months while I get ready to purchase and receive my kit, as well as all the planning I need/want to do.
I took the donor car down to my local Firestone Auto and asked them to give it a complete inspection and report back. Amazingly, the car is in really good condition to have 262,000 miles on it. Here are some the major quirks:
rear main seal leak, seems normal and expected considering the mileage
front seal leak on the differential, ditto #1
differential cover leak, ditto #1
Here's my plan for the next 6 months:
Drive her daily for the next 6 months
Figure out the differential/rear end. This Ford Explorer read end has 3.73 gearing, 8.8 " spacing. I'm hoping to use it for my kit
Engine (Plan to rebuild it myself as I've always wanted to do this)
locally who is going to do my engine machine work (those folks are starting to retire and the market demand is just not what it once was)
what transmission am I going to use
plan to use an Isky cam
refresh the GT40P heads w/ some light porting work, roller lifters, valve spring upgrades
replace all the bearings internally
hope that I don't have cylinder work to be done, won't know until I open up the engine
Need to get the garage ready for all the boxes I'll need to keep
One of the best things I've done is pay $20 to someone on EBay and purchased the Ford Service Manual. It provides ALL the details, i.e. torque specs, how to remove the engine, how to rebuild the engine, etc. Simply awesome.
I'm open to comments, suggestions or things to avoid, so let me know what you think.
Rear end widths. You want the 59.5" width if possible.
Mustang 8.8 (ring gear size) Rear End widths per year
1987-1993 - 59.5" Width
1994-1998 - 60.8" Width
1999-2004 - 61.25" Width
Last edited by Ducky2009; 02-02-2025 at 11:57 AM.
MK4 Build #9035 Delivered 2/17/17, First Start & Go-Kart 6/2/17, Licensed 9/1/17
Paint - Lightning Blue Metallic, No Hood Scoop, No Stripes
Gen 2 Coyote Engine & TKO-600. Solid Axle, 8.8-3.55, Power Steering, Power Brakes, Dual Roll Bars
Heater and Glove Box, Drop Trunk, Wipers, Radio, FFR Vintage Gauges, Custom Dash
Build Thread: http://thefactoryfiveforum.com/showt...MK4-Build-9035
Like the other mentioned that axle housing won't fit the FFR car. However. Keep the axle gears and carrier (Part the ring gear bolts to) THey fit other 8.8s Most all OEM mustang axles Did NOT come with a 373 gears but usually 2.73 or 3.08
When selecting headers to use be aware the GT40P has a different spark plug angle than GT40's or E7's. You can usually get by with 90 degree plug wire terminals and/or shorter "header plugs". Not that big of a deal but just something to keep in mind...
Also, with 262,000 miles the rear seal surface of the crank probably has a groove worn in it from the rear main seal. You can get a repair sleeve from Fel-Pro, IRRC... You can buy the installation tool for the sleeve or have the machine shop install it when they check the crank. Again, not that big of a deal but something to be aware of...
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I'm not sure my wife understands what I'm trying to do (though she is incredibly tolerant of me and deserves a new piece of jewelry). My kids just think of this as a fun project.
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Originally Posted by Jeff Kleiner
