You asked if they made a 1971 Cuda with a 318. The correct answer was no. They did build lots of 318 Barracuda's but not the Cuda. The Cuda trim package is for a performance version of the standard Barracuda. The smallest engine available in the 1971 Cuda was a 340 ci
Engines available in 1972, 225/6, 318, and the 340. 1973 the 318 and 340 only. And last but not least for 1974 the 360 was the only engine option.