Thread: Stock sbc305 piston question

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Got an old disassembled 305, 2 bolts, two piece rear main seal.
Now stuck with pistons for my engine - what was the compression height for engine for passanger car? Measured my old piston - 1.540, i think, but im not sure in this piston.
Summit shows very close parameters for pistons, can't decide what should i buy.

It would be nice if you suggest me any good cheap piston and rings kit (0.02 oversize, 5.7 rods, 3,48 stroke, stock engine for passanger car)

Many thanks!

1.540" is a cheapo rebuilder piston, meant to be used when the machine shop cuts the block decks to get a fresh finish on the decks so that the motor will seal up. Sometimes fellows will use the 1.540" piston because they don't know any better, but the correct piston for your motor is the 1.560" piston compression height. With any piston at top dead center, you should stand a steel rule on its edge and hold it about 1/4" away from the edge of the cylinder bore. Use feeler gauges between the piston crown and the bottom of the steel rule to find out how far down in the bore the piston is. This is called piston deck height, as opposed to block deck height, the measurement from the centerline of the main bearing bore to the block decks where the heads bolt on. The blueprint measurement from the piston crown to the block deck is 0.025", but this can vary due to manufacturing tolerances, whether or not the decks have been cut in the past and compression height of the piston. Measure like I said, post the results and we will go from there, finding you pistons and head gaskets that will work for you.

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