I bought an engine for the Ka Monday, going to get started this weekend. It seems like its been built to love boost, but its just not running it due to a standard intercooler at the moment. Have a receipt for a £700 rebuild and it hasnt been used since (engine has 40k on it). Here's the Spec:

T3 hybrid (double blades, .48 housing and -31 actuator)
1.5 o/s Acrylite pistons
Felpro uprated head gasket
modified con rods
non std cam
non std chip (i'll have a look on the weekend)
... along with an Escort Cosworth fuel pump that i have here.

All on the basis that i stick a dirty great big cooler on the front.

 

i run 21 psi on mine, with a grs fmic, similar spec to yours, but mine is low comp, not sure if your pistons have the compression ratio machined to low comp

 

By all accounts it is low compression.