Okay, let me lay this one on you fine people:

I have a set of piston all stamped with "14096478." I don't know anything about what they were pulled from, other than that it was a newer style, 1-piece rear main seal 350 4-bolt. They're flat tops, and I'm guessing forged.

That sure looks like a Chevy part number, but I called GM and they said it was invalid. Since one of these pistons is cracked, I'm looking for a replacement.

If anybody can help me identify what engine these things might have come from and what the most similar substitute would be, I'd be very grateful.

 

The # on the piston probably doesn't show up in the listings as GM sells pistons and pins as a assembly under a different part #
Do they look like this?
used in Vin K Chevy truck engines from 1991-1996


If nothing is available from GM then you are going to have to cross reference to a replacement from Sealed Power or similar.May have to check dish size first

 

^^Bingo, those are it.

Thanks so much for the ID and the explanation! ThirdGen never fails to spread some knowledge around.

 

Those are most likely trw or sealed power numbers, the L82 464664 piston used by GM was a TRW part number, that might be a sealed power one right there. With 2 reliefs looking identical in size to the L82 piston I'd say they are at least a 14cc dish (2x7)

In the chevy power manual there are very similar part numbers listed like that in the pistons section but they're not the GM part number. The GM number is for a piston w/ pin and rod combo. The tables in the book however do list the TRW and other part numbers. Like 464664 for the L82 piston, there are numbers there that are the same as yours apart from the last 4 numbers. That makes me believe they are sealed power numbers.