This set of six pistons, with pins, can be used in a 250ci block (with the stock connecting rods) to increase the compression ratio.  A stock piston has a compression height of 1.500, whereas the 255ci pistons have a compression height of 1.585, which raises the piston .085 in the block, thus increasing the compression ratio.

SPECS: Flat tops (with 4 valve reliefs) - 9.0 CR, Bore 3.680, C/H 1.5850, Pin Dia. 0.9122, Ring Grooves 2-5/64 & 1-3/16. Available 20,30,40 over. (Note: CR is approximate, as it will vary depending on combustion chamber size, deck height, gasket thickness, etc).

NOTE: These pistons use to be fairly easy to locate, but many suppliers have dropped them from their product line due to  low demand. While we try to keep at least one set of each bore size in stock, it may take a few weeks to fill your order if we happen to be out.