There is currently AC Delco's in there but since the motor has been rebuild i don't know what kind of plugs i should buy for it. I know its got stock heads in it, they were milled and rebuild however. The motor came from a 72 pickup truck. Here is all the specs of it that i know of:
- Flat-top Hyperutechtic pistons 8.5 to 1
- Head milled .020, Block .010
- 3 angle valve job
- Stainless valve
- .030 pistons
- X rods, ARP bolts
- crank turned .010 .010
- engine line bored
- R.V. cam (3 steps over stock)
- Rhode lifter
- Final Compressions 9.6 to 1
- 63cc hoods
- True Roller Timing Chain

thanks

 

What heads? (casting #) Or, "stock" from what? Are youcertain that even if they came off that truck, they had never been changed? At the very least, you need to know whether they use washer seats or tapered seats; 72 was just about the changeover year.