as the title states my friend is offering to sell me some 720's but they look like near dam stock lol so i dont know how can i tell what can i look for?? The other one is are GSL-SE injectors also 720's ?
TwEaK

 

no GSL-SE's have 680's (in the FAQ at the top of this section)

The only real way to tell is have them flow tested. My 1000cc secondaries look pretty much the same as stock 550's.

edit: My best advice would be don't fiddle **** around with used injectors - get new or rebuilt ones, most used injectors are 50 bucks or soemthing.....you can get a rebuilt pair on ebay for a little over 100 - then you know they're gonna work rght and you know what the flow rate is.

 

type the serial number in on google and it will come up with a bunch of injector sites