Anyone have stock or stock replacement 72-73 340 Pistons?
My 340 was originally built in 73, but the pistons have me baffled. They are .040 over and have four valve notches. I was reading that 72 and 72 pistons have a smaller compression height 1.740 versus the 68-71 which had 1.840. This would have lowered the compression ratio. But measuring the compression height of my pistons, I keep coming up with 1.840. Just wondering if anyone has a later 340 and has done any measuring on the pistons, and how many notches the factory pistons had for each model year. I assume with four notches, the piston pins must be offset to reduce piston slap. It seems my pistons might be the high compression version, which would be nice (they are not forged though). Please correct me if I'm wrong. Thank you.
My 340 was originally built in 73, but the pistons have me baffled. They are .040 over and have four valve notches. I was reading that 72 and 72 pistons have a smaller compression height 1.740 versus the 68-71 which had 1.840. This would have lowered the compression ratio. But measuring the compression height of my pistons, I keep coming up with 1.840. Just wondering if anyone has a later 340 and has done any measuring on the pistons, and how many notches the factory pistons had for each model year. I assume with four notches, the piston pins must be offset to reduce piston slap. It seems my pistons might be the high compression version, which would be nice (they are not forged though). Please correct me if I'm wrong. Thank you.
