this is correct... but A/R is one thing... it is a ratio of the area of the housing... but you are correct in wanting a .63 A/R... i would say a t3/t04e OR a t3/t04b would be perfect for you... honestly they will make the same power... the E is a little larger... but you will not rev high enough on the LS to make use of this... so the B will flow enough for you... oh and i think you ment .60trim... go with a 50 trim...
-Keith