Yes you do have a TFI ignition system, but...there is a base tiing that must be achieved. Using a timing light, remove the Spout connector and verify @ the timing pointer that the base timing is 10 degrees BTDC. After verifing base timing, plug the Spout connector back in and verify that it advances. Reading your post, I'm more inclined ot think that perhaps the Ignition coil is to blame. Easy check for this is to let the truck sit several hours to cool down, then use a hair dryer or another means of heating the coil up. Once you have got it warm (Not melted), try to start the truck as you have in the past. Is it hard ot start? If so, the coil is most likely on it's way out and it's far better to replace now, rather than in 18 inches of snow like I had mine go out and couldn't get it figured out, except for your idea of a Dead battery.

Also, you TFI module is located on the distributor itself. These are known to fail due to the amout of stress they endure from the vibration, heat and other factors putting them to the extreme due to the location. Ford revised the TFI module to be located on the Driver side Fenderwell with a large aluminium heatsink. Also, try the hairdryer trick with the TFI module "IF" your diagnosis leads you there, ruling out the coil as the culprit.