At what point do you guys go from running regular to mid-grade to premium gas? My Olds had 10.5:1 compression and I was told to always run Premium, and I always did.
I am looking at a 9.1:1 350 for my Malibu and am wondering if that would require mid-grade or even premium to run nicely. Any guesstimates as to what sort of HP I could get out of that with a decent aluminum intake and 600cfm carb would be interesting to hear too. I have no idea what cam is in it, whether it has been bored, what's been done to the heads, etc. I'm waiting for more info from the seller. Just putting feelers out in the meantime. Thanks
