[Henry Schmidt]

Any competent machine shop familiar with Carrillo rods should be qualified to rebuild those rods. They may have to fabricate the pin bushings.

The pistons used in your build have the 12.5 compression ratio because they were designed to run in a completely different chamber configuration. RSR heads had a considerably different combustion chamber (much larger volume with different valve angles). That means, the valve pockets in the RSR piston do not match the valve angles in the 2.7 head. Is that OK? well, it's OK until you start measuring valve to piston clearance with any real accuracy.
The 2.8 RSR was designed to run 10.4:1 and that number was always very optimistic.