66 69 PONTIAC OHC6 PISTONS, 250 ONLY, 4.000" BORE. 35 GRAMS LIGHTER THAN OTHER P

Description

HYPER EUTECTIC {SILICONE ADDED} DESIGNED TO RUN TIGHT CLEARANCES. TOP OF PISTON IS ABOUT .020" TALLER TO COMPENSATE FOR FELL PRO HEAD GASKET. VALVE NOTCHES ARE OHC6 AND WILL SUPPORT A .025" STROKE ON A VIRGIN CRANK SHAFT GROUND .029" UNDER, OFF SET GROUND. WILL NOT CLEAR VALVES WITH A 230 4V HEAD. ABOUT 35 GRAMS LIGHTER THAN TRACTOR PISTONS.  THIS IS A KB 156 4,000" 327 PISTON, FLAT TOP. ALSO AVAILABLE IS THE KB 157 WHICH IS A DOME TOP WHICH  WOULD RUN ON A 250 1V HEAD, OR GIVE ABOUT 11 1/2" WITH 250 4V HEAD ALSO, THE KB 158 WITH A DISH TO LOWER COMPRESSION , WHICH IS THE PISTON i HAVE RUN FOR 11 YEARS. COMPRESSION READING RECENTLY WAS 140 POUNDS AND 120 POUNDS...DID NOT BOTHER TO CHECK THE REST. I WANTED TO RUN THE LOWEST OCTANE AND STILL GET OVER 40 MPG. ENGINE IS 266 CUBES WITH THE 4.000" BORE, STROKED CRANK ADDS 3 CUBES. ALL THREE ARE AVAILABLE IN 4.020 WHICH I WILL NEED FOR MY ENGINE. PRODUCTION WAS AUTHORIZED ON 7/15/2021, ESTIMATED DATE OF COMPLETION 9/15/2021.      DO NOT HIT THE BUY IT NOW BUTTON UN LESS YOU WANT TO PRE PAY. PISTON IN PICTURE WAS SENT TO ME TO CHECK VALVE CLEARANCES. TOP AND BOTTOM RINGS ARE 1/16" THICK FOR LESS WEIGHT, OIL RING IS 3/16".