In another thread thats what his mates has he wants to beat.

A15 crankpins offset ground for the extra 2mm stroke
There are pistons off the shelve late thumper dirtbikes
but will end up costing $400-450 anyways to buy 4 slugs
so best get some high silicone ones cast with modern
casting tech from CP or Arias they makes some awesome
cast pistons that challenge forgies 4 cost/performance.

Autospeed article somewhere about budget custom cast slugs.

Sleeving the block is 100-120 each sleeve to suit slugs you
supply first from footscray engine reco services.
They will just use Loctite to seal the bottom or send it
away for grouting if need be but loctite is ample.

1800cc, supercharger, water inj and 2 inch SU would be nice
with some serious pipes & 38mm in/33ex valved H89 ported head.
Few boxes would handle the power though bar a 63a or 71 series.