I don't reckon you can mix and match parts from different homologated engines.
I also reckon 3C has either the xr2, or the xs200 as the main homologated engines, with some other epa ones too:
But, the (UK only) F200 concept is to allow you to race more or less any 200hp motor. So the 2.5 200 will be fine.
Originally posted by John G
You can use yr 2.5 block as it is a standard/stock 200hp powerhead from a homologated engine.
Likewise the 15" leg is also ok as is from a homologated engine.
Yr set up is similar to anyone running an XS200 head on a 15" leg - I think there are boats with this???