Rear end=8.8" Ford The rear axle ratio can be determined by looking at the sticker inside the driver's door under "AX". There'll be either a letter or a number there that will tell you what the ratio is, and whether or not it's a limited slip differential. Codes are as follows:
G / H / 2.26
B / C / 2.47
8 / M / 2.73
7 / - / 3.07
Y / Z / 3.08
4 / D / 3.42
F / R / 3.45
5 / E / 3.27
6 / W / 3.73
2 / K / 3.55
A / - / 3.63
J / - / 3.85
Yours will most likely be an "8" code--2.73 open differential. If it has the 3.27 or 3.55 rear end, it most likely is equipped with the towing package, which consisted of slightly larger rear brakes, somewhat stiffer springs, and a choice of 3.27 or 3.55 axles.
Cold air intakes are not available as an off-the-shelf item, however many people have custom fabricated them using other cold air intakes.
Also, I would suggest taking a look at Grandmarq.net
as they have much more information on the older cars, and will be able to answer just about any question you'd ever have. My name there is the same as my name here; tell them I sent you!
Hope this helps,
1989 Ford Crown Victoria Police Interceptor
2bbl Carbureted 351W V8, ported and polished E7TE heads, Edelbrock cam
AOD Transmission with B&M Shift Kit
3.55:1 Positraction Rear Axle
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