I suggested to the main UK distributor for Wossner stuff to produce a piston to suit those cheap American rods, but they said they were going to be doing their own rod+piston package, albeit it with a silly compression ratio.

The Eagle rods have a 19.98mm small end and are designed for pistons with approx. 29mm compression height. The current Wossner zetec pistons are all for the silver-top engine which runs a 33.05mm compression height piston. The problem with running the long blacktop/american rod (and thus a shorter compression height piston) is you instantly lose a huge amount of material of which to machine out to make them low compression.. I think you'd struggle to say run 7:1 with a blacktop piston package, i'm not sure if 7.5:1 is possible, maybe just! Of course butchering the combustion chamber may drop the compression, but perhaps at the cost of det!! Badly reworked combustion chambers (even if done on CNC machines) can result in making det worse (like removing the squish band on some engines), so you would have potentially been better off running the slightly higher CR and no det!

All of this stuff has been tested, pretty much every combination does, none of this stuff is pioneering. You're best to speak to those who have tried and tested this stuff, like Ian Howell, and either buy an engine or the parts to build an engine from them. An 'internet spec' is likely to end in tears