Finally, the rare pistons have arrived in Sweden and my home! These are some of the most essential bits in my large ZL-1 puzzle!
As I understand it these were factory original installed pistons, #3947886, especially made for the 427 L88 and ZL-1 engines. Rated at 12.5 to 1 with the floating pin design.
We found them on eBay and got them for a very reasonable price also. According to the seller these are the original pistons from a 1969 Corvette with the L88 engine and the car were just driven from the dealer and back home, a trip of about 30 miles.
The original owner removed the engine and replaced the pistons with "Blue printed " stock eliminator pistons while he had the engine built for competition use in the NHRA Stock eliminator class.
They have been in storage in a box in a clean dry garage for all these years.
Of course all this could be crap and an eager sellers best fake argument but so far nothing points to that these "facts" are wrong. The pistons shows the typical signs of ageing and storing for a long time and they all seam to be in a great condition!
The hand made markings from the seller are probably the weight of each piston in pound. All the moving parts in the engine will later be fully balanced and weight adjusted. ....that's another piece in the ZL-1 puzzle.