Been in contact with Wells, has the same parent company as Champion Labs of oil filter fame. Since I still have two modules that tested good but did not run they asked me to send them in for testing. We shall see what happens.
I do consider this important since the electronics involved are difficult for anyone to troubleshoot as the Crank sensor, Electronic Spark Control, Engine Control Module, Injectors, and assorted harnesses are all involved. Even following the six page "cranks but does not run" troubleshooting procedure in the manual often leads to conflicting results and confusing results. (when I tapped the harness pin that is supposed to rattle the injectors, the cooling fan came on...)
This is why one of my later tests is something that is not very safe - inject about a 1/2 oz of gasoline into the manifold & crank. If >nothing< happens you have no fire which means either crank sensor or ESC and not injectors or ECM.
Do not know about anyone else but it is difficult for me to lay U$145 on the counter for a non-returnable part when the super lotsa lights Wells tester says the original is good but when everything else has been eliminated...
That said I converted my '88 "C" to the later Delco ignition and it seems to run very well/is smoother than with the Magnavox but it took two "recycled" sets to come up with a good one so as soon as I have another good one will problably convert the '90 also.