Interesting, the teen slugs are a bit more money. Not enough to break the bank though. I wonder the compression would be with the KB399's and a 68 cc head?
As always…. The least produced part is more expensive.
Compression calculator here. Compression Ratio Calculator - Wallace Racing
(11.57-1 at a zero deck height 60cc (TF) head and a .038 X 4.18 head gasket. 10.37-1 @ 68cc’s.)