I've been fighting two problems 1- running hotter on expressway, doesn't overheat but does run about 15 to 20 degrees hotter and comes right down when off the expressway. I've gone through everything and system is good with a 4 row, clutch fan, etc. Other problem is at cruise anywhere from 30mph to expressway speed , when you squeeze the gas it seems to have a stumble/lag for second, like a lean spot. My MSD is at 18 initial and 30 total, I have about 11.25cr and 30 is about all I can go on pump 93. Will the vacuum advance help with the overheating at highway speeds and the tip in stumble? I will be putting a innovate A/F gauge in soon.