Ford opened the order bank for the '71 351 CJ to the dealers in May '71. That is close to the end of that year's production run in the automotive world. Only 144 vehicles were produced with that engine. The '71 Q 351 was pretty much just a test run for Ford. All the manufacturers knew that stricter emissions and safety laws were on the horizon, and most of the '71 engines in their present configuration could not meet those new emissions requirements. This engine was just a sign of things to come.
The price difference over the 302 was $45.00 for the "H" 351C 2bl, $93.00 for the "M" 351C 4bl, and $194.00 for the "Q" 351 CJ. The new 351 CJ was available on all models except the Boss 351.