This Ford 427 FE side-oiler V8 was built by Holman-Moody in the late 1960s and is said to have been installed in a 1967 Shelby Mustang GT500 in 1970. The seller states the car and engine remained in storage for around 36 years before the engine was removed and rebuilt by Holman-Moody circa 2012. Jimmy Tucker reportedly carried out both builds at Holman-Moody.
It is listed on BringaTrailer and below is the link:
https://bringatrailer.com/listing/engine-69/