why do the 1993-1995 lt1's use different ac-delco spark plugs than 1996-1997 lt1's??

93-95 ac delco#41-906
96-97 ac delco#41-943

i thought all lt1's used the same plugs, are they a different thread or what??

 

Dunno---perhaps they are made of different material e.g, copper vs plats. At any rate, I would go with NGK TR55 coppers or TR55vx plats or get the iradiums. INHO, the NGKs are superior to the Delcos---at least the plats are.

 

well i know they are both platinum

 

because they're different "versions" of an LT1 if you will...Version 1 goes from 93-95 (common identifier is the NON Vented Opti) and Version 2 are the 96 & 97 Engines (commonly identified by the Vented Opti), im assuming that the opti isnt the only thing thats different in these two motors....i still couldnt tell you why plugs would be any different aside from saying maybe the different opti's put out different voltage's or the heads could be different?

 

well i know that he 95 lt1 on f-bodys was the first year for vented opti's, and 94 caprices and impalas ,raodmasters ,and fleetwoods, also have vented optis..