I have notice their are alot of aftermarket valve covers out their but they are all 4 bolt centers and I have perimeter bolts so can I still use 4 bolt covers. Or is that only for Corvettes and GTO's?

 

you need center bolt heads. the 00+ (i believe) cars had them.

 

99 and up had center bolt. 97 and 98 had perimerter bolt.

 

most aftermarket heads will be center bolt though i believe. my plan when i swap heads is to get the center bolt valve covers along with the new style coil bracket so i dont have to remove the coils piece by peice [:'(]

 

This is true, I do not know of any aftermarket head using perimeter bolts for the LS series.