I would not be surprised. Why would you want higher? If you had a Dodge D500 dump truck fully loaded with dirt and a 354 Power Giant under the hood, you sure as heck wouldn't want 10:1.
i have a 71 D300 with a 383 2bbl that started life as an upfitted camper and is feelin' her oats in the renaissance of being upfitted again as a dump truck.
that greasy mule is likely under 8:1 and does everything exactly as you'd want and all without even breaking a sweat.
if i ever have to rebuild it, damn straight she gonna stay low compression!
