The only way to do that would be to swap out the ENTIRE Engine Bay Harness, Both the Ignition Coils, Ignition Module, and ECU/PCM.
Sorry we just switch them out. To tell you the whole story my 88 LE was on the blink and my friends 87 SE'* windshield had a crack in it so he couldn't get it registared so he let me borrow his Module and coils (Magnavox). I actually looked exactly like mine but when I tried to use it in my car it some how messed it up and wouldn't work at all. Me feeling bad went to eBay and found a unit off an 87 SE also but it was the AC Delco Type II system. I don't think I paid more that $30 dollars for the entire module with the coils. Well I won the auction and he put it in and worked great.
What I am talking about should work for the Vin 3 engine but not for the Vin C. If you do a parts search on http://www.acdelco.com
for the Vin 3 you will see it shows you can use either the D1996 MAGNAVOX UNIT or the D1946A TYPE II-D/REMY but if you do a search for the Vin C it shows you can only use the D1922A MAGNAVOX UNIT.
There is more than one type of Magnavox Module and more than one AC Delco System out there. Maybe I just got lucky.
Mostly what I have seen if you have the Vin 3 you can switch the Magnavox out with the appropriate AC Delco but if you have the Vin C the only thing is avalible is the Magnavox. If you were looking to do this with you 91 LE you are out of luck because the only thing that was offer for the 91 was the Vin C.