Looks like someone cut the top of the piston in a lathe to lower the pop-up, scuff sanded it to reduce the machining marks, and hand-stamped numbers to make it appear as if it were a stock legal Briggs piston to fool the tech man?
Sure doesn't look like any stock markings I've seen...as a tech man, I'd be digging a bit deeper.
I thought those marks looked a little funny.
That would sure be some tedious work stamping all that buy hand.
Or it is the 200 times magnification of the piston top that makes it look that way .
I would run it as is.
On a side note if its out of the engine ; is there not a spec from pin to piston top?
It's the way many companies identified various parts.
It's not done by hand. It's don on their machine.
It's and OEM Briggs piston.
Now days i believe it's done with a laser.
Here's an example of a New Model 20 or 21 Briggs piston.
Look closer at how the indentations are spaced, (specifically at the arrow.)
I'd be pulling that one apart and taking a lot more measurements (c/h, rod length, stroke) of the rotating ass't before even thinking of running it in a race where there could be tech.
Then again, there's so little tech anymore, you'd probably be alright.
Briggs crank with an altered piston. They tried to disquise the Piston because there is no animal piston that will fit the Briggs crank. They figured if they put the print on the Piston a not so knowledgeable tech wouldn't know if he was just looking for print on the Piston. JMO
Thats not making sense, Don. "There is no Animal piston that will fit the Briggs crank"
Is this what you meant?
If you want to use a Wiseco piston in a Briggs there are multiple ways to do it. You can use a stock crank and a 6248 rod or a stroker crank and a 6240 rod. If you put a deck extension on and re-sleeve it there are rods for that also.