Not sure where the limit is on pump gas cruising, but i would think 13:1 is gonna want more than 93. Depends alot on the cam. I have a 12.5:1 511 and just keep good gas in it at all time because i'm in the throttle all the time on the street. I do all my wide open testing on the freeway now because the car will run 60 to 110 in 4.5 seconds. I only use a 100 octane mix of 1 5 gallon can of Dragon 110 to 10 gallon of sunoco pump 93. I use to run it on 93 pump when it was 11.25:1 compression no problem. My cam is only 270@50.