the point of the USDM only engine rule is compliance enforcement and staying away from small run homologation specials which we colonists rarely get.

a USDM/STL spec B16A is no different than the same B16A2 or A3 REGARDLESS of the stamping on the block. that's all it is, stamping.

a JDM B16B, however, is verboten unless specifically allowed by the CRB/STAC and added in the allowance table in the GCR. same would be true of some odd JDM intake as in tGA's example. the installed engine is the engine you say it is. "This is a B16A2" means so long as it matches that description in ALL relevant ways, you're good. it could say B18C5 on the block and you could STILL be compliant (to use a USDM part swap reference)

and As far as I can see - the same IS allowed in IT. foreign sourced blocks no different than a USDM one match the letter of the rule.

happy Turkey day everyone - I'll be racing this weekend, in a way underbuilt MR2 on street tires having fun and getting passed.