The 1957 Corvette that we won the SCCA race at Riverside in 57 was clocked on the back straight @ 156.
I had some good "times" back then, too. (Back when you had to wind the stem on the clocks!) Actually, your "times" could have been even faster: those old tires would "grow" on the rim, and would indicate a slower speed on your speedometer.
New tire technology has made "citizen racing" much safer.