fuel injector help?

Hi my friend has an ls/vtec he is almost done with. Today he dropped one of his fuel injectors and it broke, now my question is how do you tell what fuel injector goes to an LS. He has literally like a pile of other fuel injectors but he does not see any numbers or codes on the old one. How do you tell what fuel injector goes to what engine, is there a way to find out?:banghead:

if his setup is obd1, then, any obd1 240cc injector.

if its obd2, any 240cc obd2 injector.

a used injector will cost you $15 - $20 if you cant figure out whats what in a pile of injectors ;)