In the middle of a 360 build. Pistons that came out look like stockers, but are larger (my calipers are reading about 4.036) and have "992P" raised up on the inside of the skirt. I have no visible identification marks for overbore on the piston anywhere. Anybody have any ideas?

(Asking now before I take a two-hour drive to my machine shop.)

https://www.summitracing.com/parts/stl-992p ?

From the link John posted, the 992P is a sealed power number (tho that one ain't a SB or possibly even a Mopar piston). What you have I'd say a garden variety 30 over sealed power cast piston. Any valve reliefs on top?

Blazin' Bob, you didn't go to the ebay link. There you see the 992P is an Ertel part number for a 360. There were several piston manufacturers around back in the day: Ertel, Zollner, Nylen, Badger, Sealed Power, etc. Their part numbers were all over the map. Confusing at best.

One measures the piston diameter at the skirt about an inch up from the lowest point. If there was a manufacturer's catalog it'd say exactly where. If the OP has already measured 4.036 on the piston, the piston is most likely 0.040 over. The cast pistons with steel "autothermic" inserts were usually installed with 0.001" clearance.

R.

No valve relief, but the caliper doesn't lie: 4.040. For once, I'm pleasantly surprised with what I find in an engine. Thanks for the help!

Enjoy it while it lasts!. Yes I missed the measurement you posted, My buddy Dog is keeping me straight (as usual!).