You dont need to burn 91+ octane, if you want get up and go,
then just fill it up with premium.
I dont burn that premium all the time,
Unless it starts knocking or I want to "pound the streets"!!!!!!!!!!!!!!!!!
Screw those springs !!
Those sprints would make it look jacked up in the rear and would throw the weight distrubution off, making the front dive when you brake hard.
RSM/Z Spec has them for $300(used to be $250?) they are 1.6" all the way around.
http://www.z-spec.com/catalog.htm
From what I have heard Eibach springs are the Best.