1990 Lincoln Towncar help

I know this is the section for the Crown Victoria, but since my Lincoln shares the same platform maby someone will have the answers I need. I'm in the middle of doing a brake job, the passenger side rotor was destroyed, after spending a fortune on new hub/rotor assemblies, and bearings, I went to compress the brake caliper piston and discovered it would seize halfway, great, now more parts, Oreilies here has the calipers with the metal pistons in stock, but mine comes with phenolic pistons,
are the two interchangeable? and is there a particular reason Ford is using plastic brake caliper pistons? I also discovered the wheel bearing cages were plastic? who's genius idea was this? I replaced them with the Nappa high grade bearings, which are all steel. I couldn't get the information on the proper grease, I used the Nappa high quality nlpg wheel bearing grease rated for disk brake cars. It says something about a Ford spec, which I found out is related to Broncos, but these are old fashioned timken type roller bearings, I don't see any issue with the grease, I won't have any compatibility issues as there is no trace of the old grease left.

Calibers: Ford, in a cost saver, went to using phenolic pistons. You cannot use steel pistons in caliber made for phenolic pistons, OR visa versa. You can change the entire caliber assembly for steel, or change them over to phenolic as AN ASSEMBLY. NEVER make the mistake of putting steel pistons in a caliber made for phenolic;that WILL destroy it.

I use www.RockAuto.com for ordering my parts for all my vehicles. I get better prices (even with the shipping), but that is only if I plan a job ahead of time. When the car breaks down on Friday and you need it Monday morning, the locals aren't too bad.

And you are right, the Town Car, Grand Marquis,and Crown Vics, all share the same platform. There are subtle differences. The TC is more of a luxury version of the CV P71. There are a few websites that are directly related to the TC.