My Ls1 is stock internally, but I've had good results (but no UOA yet) on Red Line.
I used to drag race it, but now just autocross/track days and hard street driving.
What I do is change the oil once a year around New Years time with straight Red Line 5w30.
Then around the start of summer I change the filter and dump ~ a quart of the 5w30 out of the sump and add 2 Quarts of Red Line 10W-40.
This brings the 100* cSt right up to where it can handle any type of heat we will ever get in our area.
Unlike some other companies' products, Red Line's oils CAN BE mixed/blended with each other!!
As others have stated, I also use Amsoil's EaO oil filters exclusively now.
I used to drag race it, but now just autocross/track days and hard street driving.
What I do is change the oil once a year around New Years time with straight Red Line 5w30.
Then around the start of summer I change the filter and dump ~ a quart of the 5w30 out of the sump and add 2 Quarts of Red Line 10W-40.
This brings the 100* cSt right up to where it can handle any type of heat we will ever get in our area.
Unlike some other companies' products, Red Line's oils CAN BE mixed/blended with each other!!
As others have stated, I also use Amsoil's EaO oil filters exclusively now.