It depnds upon vehicle weight, head design, head material, altitude, engine condition, engine design, ignition control, camshaft duration and a host of other factors. Is this a Cougar we are talking about, if so what is the engine and its specifics?
I'd like to hear some specifics about your setup... 400 HP is what caught my eye. I'm set up almost too wild for the street and I don't hink I'm at 400... But then again I'm not the smartest engine builder!! You can email if you'd rather...
Seems like a more agressive cam (longer duration, more lift, more overlap) takes some of the curse out of the higher compression ratios for pump gas.
Is your cam set up straight up, or is it advanced?
It's actually a guess ronzoni. Maybe I should not guess. The guess came from an article about a '68 I saw in a Car craft magazine and I have the same set up as the guy in the mag had and he was dyno'd at 415hp. My cam does have a little less duration than his did, but more lift. I'm running a Comp Xtreme energy 230/236 @050 with 520/527 lift. 10.5/1 compression. I have the cam set straight up. Big loss in low end especially since my rear gears are 3.00. I haven't had mine dyno'd so like I said, it's really a guesstimate.