they look like a low comp mahle to me the 1.00 ont he crown means it should fit into a bore that has been bored out to 100,000 over size

the engine should have been bored twice
ie 50,000 took of f the bores first time
2nd time its been bored another 50,000
so it is now 100,000 over size and these are the psistons it will need!

think u can only get 150,000 oversize pistons before the block cannot be rebored!

they should give u a near to a 1700cc engine !