Here are pictures of a couple of original Cobras that were retrofitted with 427 SOHC engines back in the seventies:
The one above is CSX3270, Carter Gette's Cobra as it appeared at SOA I in Reading, PA, in August, 1972.
The one below is CSX 3208, John Bloeman's car at SAAC I in Oakland, CA, in August, 1975. John has the side panels pulled down so that he can adjust the timing chain before making his DRIVE back home to Colorado (no trailer queen, this one!).
regards,
Jeff