Oh - and performance is awful if I squeeze the throttle at 2000rpm - feels like knock retard (although my scanning laptop is broken so I cant check).

HOWEVER... All cam lobes look shiny and new, except #6 intake which seems extensively pockmarked.
What next:

1. Heads off to inspect pistons?
2. Reassemble with new lifters and decent intake gasket(s) - throw seafoam into the intake and hope it removes the carbonation?
3. Do a proper job and also replace the cam (and at the same time, of course, upgrade the timing chain, install a later model opti and timing chain cover, plus electric water pump..?4. To hell with it, sell the motor and supercharger for parts and install a crate motor....