I could be mistaken, but I do seem to recall one or more of the early Cobra dragsters, modified, did run in the 10's. BUT that car would have been illegal under the 'stock' class rules at the time. 289 'Hi Po' heads were illegal for instance (not to mention twin turbo)
The Harr Ford dragon snake in LEGAL competition was running in the mid 11's with a trap speed in the 120's (and it had a black hood)!
Make no mistake, 10.3 is incredibly fast, small or big block, it's an awesome number!