I have valve springs that I know little about. They came in an LS3 that had been previously opened up with unknown history. The camshaft in this engine was from an LS9 based on the numbers on the end of the cam. Does anyone have a clue what these valve springs could be? My intention is to use them in 862's in my LM7 (iron 5.3). I'm looking for a well behaved street engine in a 3500lb car. I'd like to go between 500 and 560 lift but I'm open to thoughts. I may take the bore out to 3.89 (5.7). I'd go with more bore if I thought I could get away with it . Anyone know what these springs are?

 

I just pulled some stock springs that had the same markings/color from an 08 5.3 Springs do wear out so my advice is to just buy new based on what's recommended by the cam manufacturer.