[kenikh]

Dialing out timing is not ideal, but will work on DME motors. Another thought is to drill for twin plugs, clearance the plug hole like the stock one, then close the hole with a fastener flush to the head. That will rebate a cc or two, drop compression a bit and leave you ready for modifications in the future. DME high compression pistons can also accomodate about 1mm for a valve pocket to clear high lift cams, so you could take a little material off the piston to decrease compression even more. With 964 cams, you'd be right in the sweet spot of compression without crappy timing.