Please help with piston/barrel identification

[Wiggy]

I just accepted a Sonex Waiex project to finish. I don’t have anyone that I can ask about the history. This engine started as a 2180. Then became a turbo. It has not been run since the barrels and pistons were swapped.
One set (not pictured) of piston and barrels where bench run on a test stand (I assume at AeroVee). I’m guessing that these are Nikasil.
The pictures are from another set of unused pistons and barrels. I think it has C70JK stamped at the bottom of the barrel.
Can anyone tell me what these are? What they can be used on?

[Sonerai13]

You can readily tell the difference between Nikasil cylinders and steel simply by lifting them. The Nikasil cylinders are MUCH lighter. But you can also use a magnet to identify them. If the magnet sticks, the cylinders are steel. If it won't, they're Nikasil. If they're steel they can be used on any engine, including the turbo. Measure the bore too, to make sure they're 92 mm (assuming you're working on a 2180 cc engine.)

[Wiggy]

Thank you, Mr. Norris.
They all have 91.93 stamped on the piston head. Can I tell anything about compression ratio by looking at the piston dome or skirt, or these codes (looks like the AeroVee logo to me)? I acknowledge that the Nikasil box weighs a lot less than the box full of steel barrels and pistons.

[Bryan Cotton]

If you download the Aerovee manual you will see compression is set by deck height, which is set by shims on the barrel. Actually just downloading it is not sufficient - read it too!

[Wiggy]

Actually just downloading it is not sufficient - read it too!

Guilty. Thank you, sir. I have it downloaded, but had not managed to read to page 22.