Good morning, well I miss read it's not 420 words it's 420 characters. I have an 07 GT manual 127000 . I prefer to run 87 as 91 is 30 miles away. PO put on Roush CAI no tune needed. Can I run LTH,UDPS, original intake & TB or am I just wasting money running 87 oct. I don't feel I drive the car hard, no track car. I do have a SCTx4, thanks.