factory mods

V

vkessler

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ok so i went to take off my glove box door today, to replace the lock itself and under my dash there is an old decal it reads Ford authorized modifications
M-4204-t28
M-4209-g355m
yo-1
after that it has a dealer number, date aug, 19, 1993
and a change authority number. Can anyone tell me what was done to my car i don't know where to look to see
 
ok so i got home and googled the numbers on the tag, a guy i work with said it may be worth a shot and those numbers match ford racing products an 8.8 diff and 3.55 gears still had no luck on the last 1, is it possible my car came with these? i thought it only had one gear option for the 93. any suggestions.
 
NO Marks came with 3.55's, you're out of luck, lol. If yours is a base model you have 3.07's, if its an LSC you have 3.27's. Thats it....oh and all of them were open diffs and all of them were 8.8's, haha.
 
If you really want to verify it, slide under the car & check the differential tag.
If I recall correctly, it won't read 3.27 but 3(blank space)27.
TracLoks will have an L after the numbers.
Maybe you'll see 3(space)55(space)L.

Mel C.
 
The Drill-man is correct. You could order factory modifications for just about any Ford product in the 90's. What a car rolled off the assembly line with, is not always what it was delivered with.

I dont know about 2009 vehicles, but you could still "build you own" on many cars, up until last year.

Many people walked in to a dealership and ordered cars, and dealer/factory modifications and waited for them to be delivered.

I wouldn't hesitate to believe your Mark VIII came with non-stock parts.
it's simple to tell really...get on the freeway and go 70 mph in OD and tell us if the tach reads higher than 2100 rpms.

I too am puzzled with the yo-1.
could have been an installation kit, that Y could be a V which is Lincoln's code.

pretty cool set up you have there.
 
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Very True. I had forgotten about this, in the mid 80's I want a custom Bronco. I talked to the dealer but ended up not going through with it. A couple months later the dealer called me to tell me they had the truck built anyway and wanted me to come see it. I wonder what happened to it!

Do check the RPM's and the tag should be there also.
 
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ok so coming home from work this morning im doing 70mph and my tach reads around 2250-2300rpm i don't know if that means a lot cause i don't really know the stock numbers, i do know my buddy has a 94 and i've always had him on take off. i always thought it was better reaction, maybe not. i'll try and get pics up as soon as work lets up we got ot and 60 hrs a week are rough.
 
you have 3.55's

stock base Mark VIII(non -LSC) will show 1900-2000 "ISH" RPMs at 70 mph.
LSC w/3.27 gears will show 2100 or so

based on the tag you located, which was placed in the correct location, it would appear as though your car was special ordered for someone, and came equipped with factory parts that were not 'standard' on the Mark VIII.

although 3.55's are a more "performance" type gear set, they are not going to provide a whole lot of measurable improvement over stock simply based on the small incremental change in ratios. The Mark VIII has a wide-ratio transmission, so the gear ratio's inside are very spread apart. going from 3.07/3.27 to 3.55 is not much more than a tire size change. What it will do is provide you with slightly better 0-60 times, and improve throttle response in the mid-range speed department.

Your fuel economy shouldn't suffer much, but the best part is, you have a TRAC-LOC in there...both tires are now working properly out back.

I'd be stoked with 3.55's. Besides, you have a great conversation piece now.

I believe that yo-1 code is probably an internal "installation" code, or a "installation kit/order" code, not related to a particular part...just an order number, or destination/modification location type. code.

I could be wrong.
 
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