Nope the tuck was totaled, I bought it back and sold it for a friend who needed the front axle and some body panels to fix her Excursion. Plus I bought it two months prior to the crash for $7,500 and they gave me over $12k totaling it out.

I bought my current 2002 Ex 15 days after that crash.

 

Good deal.
I did a little checking and found a couple frames local'ish for $500. I'll likely just do that and clean / paint everything during the swap. Thanks for the reply.

 

I know I am extremely late to the game on this, but I may be able to shed a little light on the part number differences. If you notice, Frames 1, 3, and 4 in your list all have the same part number, except for the last two characters. Those characters indicate minor changes to an otherwise identical part. So, say one chassis cab needs an additional set of mounting holes, the other chassis cab needs two additional sets of mounting holes, and the pickup doesn't need any of those mounting holes at all, then they all get the same basic part number but with differing 2-character suffixes. A running change on the factory floor would also change a suffix.

As for the Excursion prefix difference, the only reason it is different is because Ford changed their numbering designations in 1999. You have to remember, they began producing the 1999 model year trucks in 1998, so truck frames went by the old numbering system, and 2000 model year Excursions started production in 1999, so they went by the new numbering system. The old part numbers always go by the year they were first produced, so if you're ordering a front frame for a 2002 truck, the part number will still code out to the 1999 (made in 1998) number. The new number system switched to calling out the model year. There still could be some difference to the Excursion frame- something in the crumple zone, maybe?

Using the prefixes of your examples-
F81Z-
F is the 1990's decade
8 is 1998 (manufacture year, NOT model year)
1 is F-250/F-350
Z is Ford Customer Service Division (because this is a replacement part, not meant for factory assembly)

YC3Z-
Y is 2000 model year (yes, the new number system switched to model year instead of manufacture year)
C3 is medium truck (see that? Medium TRUCK)
Z is Ford Customer Service Division

The middle characters are the actual part number that designates that we are talking about a front frame assembly.

Hope this helps.

 

It may just as likely harm instead of help, as a portion of the post minimizes the potential significance of a letter change in the suffix. A single letter change in the suffix can make the difference between the part fitting or not fitting the application.

The basic part number 5C145 applies to front frame sections of all kinds of Fords... F-150, Escape, Expedition, Explorer, Excursion, Etc. (speaking of all these E's, Ford should have made a catch all cross over vehicle called the EtCetera). Everyone will agree that these vehicles all have very different front frame sections, or subframes for the unit body types, and yet the basic part number applicable to all of them is 5C145. How Ford parts delivers the right part for the application is determined by the prefix (encoding the design release or revision year and general platform) and suffix (encoding model specific, application specific, option specific, color specific, or other specific differences).

Here is the front frame section 5C145 part number to my Ford Escape:

Clearly, the 5C145 depicted above has more than just a hole or two difference between it and what we find under an Excursion.

The amount of difference can vary vastly by the type of part. Sometimes the differences are insignificant. If an interior sun visor broke, and one needs a sun visor to drive safely when facing the sun, then the suffix letter distinguishing Graphite from Medium Parchment... while significant if the truck was brand new and still under warranty... is not significant when the truck is 20 years old, the part has long been discontinued, and one still needs the function of a sun visor.

So while there is no argument that the numerology sequence explanation in the latter half of the post quoted above is true, the initial minimization of the significance of the suffix letters following the basic part number can potentially mislead people into disappointing parts purchases, so in the interests of maintaining the accuracy of information found on our forum, this point needed to be clarified and reiterated. All the letters in a Ford part number matter. Suffixes are significant. Sometimes more, sometimes less, but always significant.

This clarification isn't meant to say that a Ford F-350 front frame section cannot be adapted to an Excursion main frame section. It is simply to clarify the original question... which is yes, there are differences between the front frame sections.

Are those differences related to cross-sectional material thickness?

Are those differences related to tab flange mounts integrated into the front spring hangar base weldment on the front frame horns to mount Blocker Beams that were not mandated on chassis cabs or over 10K GVWR back at that time?

Are those differences related to frame mounted heat shielding on the passenger side frame rail for the A/C lines to the rear A/C of the Excursion that trucks don't have?

I don't know what all the front frame differences are... but Ford parts numbering indicates that there were differences, and the application listings detailed below bear this out.

YC3Z-5C145-AA applies to: (before production date 11/04/2002)
Ford Excursion 5.4L Triton V8 A/T 4WD Eddie Bauer Sport Utility 2002, 2003
Ford Excursion 5.4L Triton V8 A/T 4WD Limited Sport Utility 2000, 2001, 2002, 2003
Ford Excursion 5.4L Triton V8 A/T 4WD XLT Sport Utility 2000, 2001, 2002, 2003
Ford Excursion 5.4L Triton V8 A/T RWD Eddie Bauer Sport Utility 2002, 2003
Ford Excursion 5.4L Triton V8 A/T RWD Limited Sport Utility 2000, 2001, 2002, 2003
Ford Excursion 5.4L Triton V8 A/T RWD XLT Sport Utility 2000, 2001, 2002, 2003
Ford Excursion 6.0L V8 DIESEL A/T 4WD Eddie Bauer Sport Utility 2003
Ford Excursion 6.0L V8 DIESEL A/T 4WD Limited Sport Utility 2003
Ford Excursion 6.0L V8 DIESEL A/T 4WD XLT Sport Utility 2003
Ford Excursion 6.0L V8 DIESEL A/T RWD Eddie Bauer Sport Utility 2003
Ford Excursion 6.0L V8 DIESEL A/T RWD Limited Sport Utility 2003
Ford Excursion 6.0L V8 DIESEL A/T RWD XLT Sport Utility 2003
Ford Excursion 6.8L Triton V10 A/T 4WD Eddie Bauer Sport Utility 2002, 2003
Ford Excursion 6.8L Triton V10 A/T 4WD Limited Sport Utility 2000, 2001, 2002, 2003
Ford Excursion 6.8L Triton V10 A/T 4WD XLT Sport Utility 2000, 2001, 2002, 2003
Ford Excursion 6.8L Triton V10 A/T RWD Eddie Bauer Sport Utility 2002, 2003
Ford Excursion 6.8L Triton V10 A/T RWD Limited Sport Utility 2000, 2001, 2002, 2003
Ford Excursion 6.8L Triton V10 A/T RWD XLT Sport Utility 2000, 2001, 2002, 2003
Ford Excursion 7.3L Power-Stroke V8 DIESEL A/T 4WD Eddie Bauer Sport Utility 2002, 2003
Ford Excursion 7.3L Power-Stroke V8 DIESEL A/T 4WD Limited Sport Utility 2000, 2001, 2002, 2003
Ford Excursion 7.3L Power-Stroke V8 DIESEL A/T 4WD XLT Sport Utility 2000, 2001, 2002, 2003
Ford Excursion 7.3L Power-Stroke V8 DIESEL A/T RWD Eddie Bauer Sport Utility 2002, 2003
Ford Excursion 7.3L Power-Stroke V8 DIESEL A/T RWD Limited Sport Utility 2000, 2001, 2002, 2003
Ford Excursion 7.3L Power-Stroke V8 DIESEL A/T RWD XLT Sport Utility 2000, 2001, 2002, 2003

F81Z-5C145-AB applies to: (before production date 11/04/2002)
Ford F-250 Super Duty 1999, 2000, 2001, 2002, 2003
Ford F-350 Super Duty 1999, 2000, 2001, 2002, 2003
(All engines, All wheelbases, All drivelines, All cab styles, All pickups)

F81Z-5C145-BA applies to: (before production date 11/04/2002)
Ford F-350 Chassis Cab 1999, 2000, 2001, 2002, 2003

F81Z-5C145-CA applies to: (before production date 11/04/2002)
Ford F-450 Super Duty 6.0L V8 DIESEL A/T 4 X 2 Lariat Cab & Chassis - Crew Cab 2003
Ford F-450 Super Duty 6.0L V8 DIESEL A/T 4 X 2 XL Cab & Chassis - Crew Cab 2003
Ford F-450 Super Duty 6.0L V8 DIESEL A/T 4 X 2 XLT Cab & Chassis - Crew Cab 2003
Ford F-450 Super Duty 6.0L V8 DIESEL A/T 4 X 4 Lariat Cab & Chassis - Crew Cab 2003
Ford F-450 Super Duty 6.0L V8 DIESEL A/T 4 X 4 XL Cab & Chassis - Crew Cab 2003
Ford F-450 Super Duty 6.0L V8 DIESEL A/T 4 X 4 XLT Cab & Chassis - Crew Cab 2003
Ford F-450 Super Duty 6.0L V8 DIESEL M/T 4 X 2 Lariat Cab & Chassis - Crew Cab 2003
Ford F-450 Super Duty 6.0L V8 DIESEL M/T 4 X 2 XL Cab & Chassis - Crew Cab 2003
Ford F-450 Super Duty 6.0L V8 DIESEL M/T 4 X 2 XLT Cab & Chassis - Crew Cab 2003
Ford F-450 Super Duty 6.0L V8 DIESEL M/T 4 X 4 Lariat Cab & Chassis - Crew Cab 2003
Ford F-450 Super Duty 6.0L V8 DIESEL M/T 4 X 4 XL Cab & Chassis - Crew Cab 2003
Ford F-450 Super Duty 6.0L V8 DIESEL M/T 4 X 4 XLT Cab & Chassis - Crew Cab 2003
Ford F-450 Super Duty 6.8L Triton V10 A/T 4 X 2 Lariat Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 6.8L Triton V10 A/T 4 X 2 XL Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 6.8L Triton V10 A/T 4 X 2 XLT Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 6.8L Triton V10 A/T 4 X 4 Lariat Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 6.8L Triton V10 A/T 4 X 4 XL Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 6.8L Triton V10 A/T 4 X 4 XLT Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 6.8L Triton V10 M/T 4 X 2 Lariat Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 6.8L Triton V10 M/T 4 X 2 XL Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 6.8L Triton V10 M/T 4 X 2 XLT Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 6.8L Triton V10 M/T 4 X 4 Lariat Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 6.8L Triton V10 M/T 4 X 4 XL Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 6.8L Triton V10 M/T 4 X 4 XLT Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 7.3L Power-Stroke V8 DIESEL A/T 4 X 2 Lariat Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 7.3L Power-Stroke V8 DIESEL A/T 4 X 2 XL Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 7.3L Power-Stroke V8 DIESEL A/T 4 X 2 XLT Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 7.3L Power-Stroke V8 DIESEL A/T 4 X 4 Lariat Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 7.3L Power-Stroke V8 DIESEL A/T 4 X 4 XL Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 7.3L Power-Stroke V8 DIESEL A/T 4 X 4 XLT Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 7.3L Power-Stroke V8 DIESEL M/T 4 X 2 Lariat Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 7.3L Power-Stroke V8 DIESEL M/T 4 X 2 XL Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 7.3L Power-Stroke V8 DIESEL M/T 4 X 2 XLT Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 7.3L Power-Stroke V8 DIESEL M/T 4 X 4 Lariat Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 7.3L Power-Stroke V8 DIESEL M/T 4 X 4 XL Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-450 Super Duty 7.3L Power-Stroke V8 DIESEL M/T 4 X 4 XLT Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 6.0L V8 DIESEL A/T 4 X 2 Lariat Cab & Chassis - Crew Cab 2003
Ford F-550 Super Duty 6.0L V8 DIESEL A/T 4 X 2 XL Cab & Chassis - Crew Cab 2003
Ford F-550 Super Duty 6.0L V8 DIESEL A/T 4 X 2 XLT Cab & Chassis - Crew Cab 2003
Ford F-550 Super Duty 6.0L V8 DIESEL A/T 4 X 4 Lariat Cab & Chassis - Crew Cab 2003
Ford F-550 Super Duty 6.0L V8 DIESEL A/T 4 X 4 XL Cab & Chassis - Crew Cab 2003
Ford F-550 Super Duty 6.0L V8 DIESEL A/T 4 X 4 XLT Cab & Chassis - Crew Cab 2003
Ford F-550 Super Duty 6.0L V8 DIESEL M/T 4 X 2 Lariat Cab & Chassis - Crew Cab 2003
Ford F-550 Super Duty 6.0L V8 DIESEL M/T 4 X 2 XL Cab & Chassis - Crew Cab 2003
Ford F-550 Super Duty 6.0L V8 DIESEL M/T 4 X 2 XLT Cab & Chassis - Crew Cab 2003
Ford F-550 Super Duty 6.0L V8 DIESEL M/T 4 X 4 Lariat Cab & Chassis - Crew Cab 2003
Ford F-550 Super Duty 6.0L V8 DIESEL M/T 4 X 4 XL Cab & Chassis - Crew Cab 2003
Ford F-550 Super Duty 6.0L V8 DIESEL M/T 4 X 4 XLT Cab & Chassis - Crew Cab 2003
Ford F-550 Super Duty 6.8L Triton V10 A/T 4 X 2 Lariat Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 6.8L Triton V10 A/T 4 X 2 XL Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 6.8L Triton V10 A/T 4 X 2 XLT Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 6.8L Triton V10 A/T 4 X 4 Lariat Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 6.8L Triton V10 A/T 4 X 4 XL Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 6.8L Triton V10 A/T 4 X 4 XLT Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 6.8L Triton V10 M/T 4 X 2 Lariat Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 6.8L Triton V10 M/T 4 X 2 XL Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 6.8L Triton V10 M/T 4 X 2 XLT Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 6.8L Triton V10 M/T 4 X 4 Lariat Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 6.8L Triton V10 M/T 4 X 4 XL Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 6.8L Triton V10 M/T 4 X 4 XLT Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 7.3L Power-Stroke V8 DIESEL A/T 4 X 2 Lariat Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 7.3L Power-Stroke V8 DIESEL A/T 4 X 2 XL Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 7.3L Power-Stroke V8 DIESEL A/T 4 X 2 XLT Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 7.3L Power-Stroke V8 DIESEL A/T 4 X 4 Lariat Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 7.3L Power-Stroke V8 DIESEL A/T 4 X 4 XL Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 7.3L Power-Stroke V8 DIESEL A/T 4 X 4 XLT Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 7.3L Power-Stroke V8 DIESEL M/T 4 X 2 Lariat Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 7.3L Power-Stroke V8 DIESEL M/T 4 X 2 XL Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 7.3L Power-Stroke V8 DIESEL M/T 4 X 2 XLT Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 7.3L Power-Stroke V8 DIESEL M/T 4 X 4 Lariat Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 7.3L Power-Stroke V8 DIESEL M/T 4 X 4 XL Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003
Ford F-550 Super Duty 7.3L Power-Stroke V8 DIESEL M/T 4 X 4 XLT Cab & Chassis - Crew Cab 1999, 2000, 2001, 2002, 2003

In the parts listings above, I've only detailed the four part numbers I previously cited in the post which the quoted post above was in response to.

There are other part numbers, all of which are 5C145, all of which have prefixes and suffixes that only vary by a single leading number in the prefix, and a single ending letter in the suffix, but those small alphanumeric changes are not insignificant. They mean the difference between the mid 2003-2004 model years, the 2005-2007 model years, the 2008-2010 model years, the difference between the pickups and the chassis cabs, the difference between the F-350 chassis cab versus the F-450/550 chassis cab... etc.

The point being... order the right part number for the application. This why parts counter folks often ask for the VIN. This is a principle and good practice applicable to all Ford parts purchases.

And, having said all of that, the point in this case is somewhat moot, as all of this generation's front frame section parts have been discontinued.