The T-50 and R-50 Cammer were the first 5 litre DOHC engines Ford made, they are the engines the Coyote was modeled after, and have the most wins in Grand Am for Ford, The T-50 was rated at 440hp while the R-50 was rated at 500hp... Both were offered in the Ford Racing Catalog in 2004-2005...so there are actually 3 versions if you count the 4.6 DOHC with them...
The R-50 Cammer was the first 5 litre used in the Daytona Prototype class for racing...