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Forgive me for the frustration. I have a sbc 350 that belonged to a deceased relative. The engine was rebuilt, bored .030, new rings, new crank, new cam, new pistons, and placed in a chevy pickup. due to an accident we removed the engine and it sat for at least 10 years. I recently decided to throw it into my boat (I know...all the necessary changes have been made), however I had to free up the motor(longer story) I dropped the piston and broke it. i need to replace 1 piston. Heres the rub, the numbers on it dont identify. 946P thats it.
I need help with this asap! identifying the piston brand/replacement to match compression etc instead a whole new set. I already got the rings and honed the cylinder walls. My prep is good so please no you need to blah blah blah. I am looking for assistance with identifying the pistons. Thanks
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Really need to see the crown. What matters most is weight volumes of the crown shape and the compression height which is pin centerline to top edge where side becomes crown not counting domes or cavities.

That is one grungy piston. What do the bores look like? If the bores are decent I’d put a fresh set of pistons and rings in there.

Bogie
 

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Take it to a machine shop - have them weigh it and they should be able to find something in one of the piston catalogs that will match up pretty close. If they get one a little heavy, they can remove a little bit from it to match your broken one.
 

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More for Less Racer
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The waffle pattern on the pin boss sides looks like Federal Mogul/Sterling, which has been gone for maybe 15 years now, so maybe not likely to find an exact match. Second possibility is Sealed Power, same vintage 15 years old

The 946P number fits with Fed-Mog/Sterling numbering system around the mid 1990's time frame.

With a 350 cast single piston costing you between $25 and $40, and a whole new set just under $100 you are probably smarter to just replace the whole set....they will match each other that way.

But yeah, Chasracer is right. If you want to replace just one do like he advised.
 

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Race it, Don't rice it!
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The waffle pattern on the pin boss sides looks like Federal Mogul/Sterling, which has been gone for maybe 15 years now, so maybe not likely to find an exact match. Second possibility is Sealed Power, same vintage 15 years old

The 946P number fits with Fed-Mog/Sterling numbering system around the mid 1990's time frame.

With a 350 cast single piston costing you between $25 and $40, and a whole new set just under $100 you are probably smarter to just replace the whole set....they will match each other that way.

But yeah, Chasracer is right. If you want to replace just one do like he advised.
That's a press fit pin so include the $100 for a shop to [email protected] the pins.
 

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The waffle pattern on the pin boss sides looks like Federal Mogul/Sterling, which has been gone for maybe 15 years now, so maybe not likely to find an exact match. Second possibility is Sealed Power, same vintage 15 years old

The 946P number fits with Fed-Mog/Sterling numbering system around the mid 1990's time frame.

With a 350 cast single piston costing you between $25 and $40, and a whole new set just under $100 you are probably smarter to just replace the whole set....they will match each other that way.

But yeah, Chasracer is right. If you want to replace just one do like he advised.
I have been looking for pistons like those never even saw anything like it.
 
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