Dose anyone know if it will work on a 99 blazer?

I know a guy who tunes but hes not for sure if it will work on my blazer, But he did my friends truck with the same motor but Im not sure if the computer is the same.

 

The computer should be the same, a 4.3 in a Silverado isn't any different from a 4.3 in a Blazer. The intake may be different, but as far as PCM/ECU I'm 99.9% sure they're identical.

 

I was thinking it was but dident know for sure. My friend saw a big change in his after it was done. I just wana get mine done cuz shifts points are way early to me.

 

I"ve thought about a tune, but am a little leary, I don't want to be stuck running 91 octane.

 

Ive heard people say that before but the guy who dose the tuneing has learned how to change everything but still be the same octane. Im just geting him to change my shift points so it wont shift as soon and I can have a longer gear.