Your 93 is late enough production that it is very unlikely that you'd need to replace anything. They stopped using the ethanol-dissolvable materials a while back.

However, that gets us to whatt you'd actually need to do to your car to make it run on E85. "Flexfuel" is a term that implies your car is able to sense the amount of ethanol in the fuel, and adapt the injection accordingly. Frankly, that's just not going to happen with the Bosch LH system on your car. Here are a couple of options:

1) Mechanically switch from one fuel to another. E85 requires about 30 - 35% more fuel volume. This is more than the Bosch ECU will fudge upwards (spurred on by O2 sensor readings) before it gives up and sets a CEL. So you need to mechanically fudgge the injection volumes up, so the ECU (which really just knows how long it's opening the injectors) is in the correct ballpark for E85. You can do this by swapping the injectors for ones that flow ~30% more. That's it. The drawbacks to this are that it takes an hour or so to swap injectors, and until you swap them again you are permanently stuck on the 'new' fuel. And you can't really take advantage of the higher octane of the E85 by running more aggressive spark advance.

2) Replace the injection system with something programmable, like Megasquirt. I've got an older Megasquirt unit installed in mine (mostly because I'm running lots of boost) but it has switchable fuel and spark tables. So I can set up tables optimized for gas, and other tables optimized for ethanol, and jsut flip a switch to swap between them. So I could run the car nearly empty, tank up on the other fuel, start it, and after it runs for about 10 seconds flip the switch.

3) There is a newer version of Megasquirt (MS II) that apparently does have support for a GM ethanol sensor. I'm not sure of the exact way you set it up, but I'd suspect you have two sets of tables, and it extrapolates between the two based on the ethanol content. Or maybe it just fudges the fuel volumes somewhere between 0 and 35% based on the ethanol content. Either way, it would make the car a true flex fuel vehicle.
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'63 PV544 rat rod, '93 Classic #1141 245 +t