360 LA getting oil in #3 cylinder.

What bolts did you buy? ARP lists 144-3602 for stock heads.
What heads do you have? Some aftermarket heads required the longer sets used for many Edelbrock heads. Or you might have accidentally bought some which are intended for other heads - ARP has at least 3 different listings on summit depending on the heads.
The engine already had ARP head bolts. Those are the ones I measured.
I bought a new set of ARP head bolts #144-3602. I haven't opened the new box in case I decide to return them and go with studs. Standard LA 360 block and heads.