Tom,
You don't have the extended warranty on injectors Find out which cylinder it is and do a compression check on that cylinder and the one next to it. DO NOT CLEAR THE CODE.... Also, how many miles are on it??? If all looks good, swap coil with another cylinder and see if the missfire moves. Did the coils come with new boots? If not replace all the boots. Also check and make sure no oil is leaking from the valve cover seals into the spark plug holes, they should be completly dry. FYI the computer will shut the injector down for that cylinder when it detects a missfire. If the missfire does NOT move when you move the coil its 1) harness problem 2) PCM driver or 3) low compression caused by a bad exhaust valve. let me know what you come up with.
BTW if you unplug a coil to see if the cylinder drops, the PCM will turn that injector off to save your CATS, so you can't use that test on these vehicles. Works great on our flatheads though.