RC Injectors what is the difference between SL4 SL9 and SL10?

 

Someone has to know.....

 

From when I'm reading, its has to do with the circumference of the injector...

 

Just to clear things up, i spoke with the guys over at RC ENG. he basically told me that SL4 can be used just about with any car with machining done(almost like made to fit, like what you said circumference)

And that the SL9 is for honda /acura. He said order for your application if you want a direct fit.