The 389 and 421 cubic-inch V8s received a number of revisions including thinner wall block castings. The standard engine for Catalina models is the 389 two-barrel rated at with base three-speed manual transmission and 8.6 to 1 compression or 290 horsepower with Turbo Hydramatic transmission and higher 10.5 to 1 compression. An economy regular-fuel version of the 389 two-barrel with 8.6 to 1 compression ratio that burned regular gas was available as a no-cost option with Turbo Hydramatic. Optional engines include a four-barrel 389 rated at with Turbo Hydramatic or 333 with stick shift, a Tri-Power 389 rated at 338 horsepower, a four-barrel 421 rated at the same , 353 hp with Tri-Power or the 421 HO with Tri-Power and .