I have a mystery engine in a Camaro I just bought, 10054727 block, 14102193 heads with e09 date code. Looks like its a tbi truck 86 and newer from what I have found out. Center bolt valve covers. It has screw in studs and guide plates which is weird. Has a performer intake. Anyone know what e09 is for the date? What about plugs? It has cr43ts in there now, black and runs terrible, misses.