how can i tell if a b20 is jdm or american??

 

A JDM engine will not have a number on the end, and an American engine will.

Also if it says B20Zx (the "x" will be a number) anything it's USDM.

JDM engines were B20B with no number on the end, but they did come in "low compression" and "high compression" versions.

 

from what i was told if it has a number at the end its north American and if it has a letter at the end its jdm. for example my integra had a b18c1 (us) the jdm one was a b18c

 

haha beat me to it by a min.