01 sierra 4.8l

[Egoresb]

Just got an intune loaded the 87 octane tune and liked it. Tanked up on 93 octane little improvement. I like this tuner but I'm not quite sure what I should try to change or not to squeeze more power out of this 200k mile 4.8l any tips or suggestions on how to adjust fuel or timing? The only mods I have is a 07 4l60e tranny was told it has more beef to it than the 01 a k&n intake and flow master duels. I also see a custom tune option is it worth it for my slight amount of mods?