First, thanks for the helpful responses.
I should have mentioned that I will be playing Blackshark 2 (BS2). I also should have mentioned that the Andretti wheel system completely failed to work with the gameport to USB converter because the pedals were detected as digital button press combinations (weird!). I originally planned to use the converter with my old CH Pro Flightstick (gameport version) but the pots are completely shot on it, so I just ended up ordering another joystick which does not use pots (TM 16000). My plan was to directly wire the racing wheel pedal pots to a gameport connector. However, as Rhinox pointed out, this will not work with them simply wired in series. Looks like obtaining or building a circuit board is really the only way to go with getting these pedals to work.
I do have another pair of pedals, ACT Labs Performance pedals with separate axes for the gas, brake, and clutch. I originally tried to use these using a two axes solution using the configure axis options in BS2, but I could not get this to work well at all (c.f., http://forums.eagle.ru/showthread.php?t=52620). BS2 seems to want the rudder to be just on one axis to work well. I do not know if A10C or Lock On work differently. Would assigning say the gas and brake axes of the pedals to the wheel brakes in BS2 really work and act as rudders, Rhinox?
I was able to successfully implement Plainsight's solution of setting up a virtual joystick using the PPJOY and GlobePie software, so now I have a functional set of rudder pedals for no cost. Thanks! It took me a few hours to figure out how to do this and here is the basic procedure:
1. Install a virtual joystick with one analog axis using PPJoy device driver (http://ppjoy.blogspot.com/). This is sort of a pain because the driver is unsigned so you need to tell Windows 7 (64 bit) to allow test drivers. Do this by running "cmd" as an administrator and typing in, "bcdedit -set testsigning ON" in the console window. The bad thing about this is that you make your computer more unsecure and you have a test mode build message permanently fixed on the lower right portion of your desktop.
2. Download GlovePie (http://glovepie.org/) and set it up so that the gas pedal and brake (or clutch) work with the virtual joystick above. I found two additional programs that aid in this process. First, use JoyIDS (http://www.wingmanteam.com/latest_software/gadgets.htm#JoyIDs_Utility:) to determine which Windows ID each controller is assigned to. Then you run a GlovePie script written by Lednerg to identify what names your pedals are assigned to (http://glovepie.org/forum/viewtopic.php?f=2&t=808). You then write your own script using a formula similar to the one Plainsight used. Mine looked like this:
PPJoy1.Analog0 = .5*Joystick1.yaw - .5*Joystick1.pitch
Depending on how the axis is assigned in BS2, you may need to play with the proportions of each joystick axis some. For example, when I set the rudder to be a slider in BS2, I had to bias the left/brake pedal (yaw) slightly more than the right/gas pedal (pitch) for some reason.
As a long term project, I may try to get my Andretti pedals working with a circuit board as they have much better action than the Act Lab pedals. One problem with many brake pedals is that they have hardware which creates much more resistance the further the pedal is pressed in. I have trouble geting a 100% depressed value on my Act Labs brake pedal, for example (and the clutch only provided a limited range of values making it useless.) Thanks for the links, Sokol1. The BU0836 http://www.leobodnar.com/products/BU0836/) is another solution and one that could restore my CH Pro throttle to some degree of functionality.