Has the AAM engine changed at all during its service life?

The reason I ask, is whenever I go and get parts the AAM engine is listed twice, something like 90-94 and then 94 on....

Was it a change to fuel injection in '94????

Im currently looking at getting a set of splitfire ignition leads, they are listed as up to 94 on an AAM engine, why would they not work on post 94? different dizzy??

Thanking you all in advance for any advice

Cheers