Rustaddict is correct about value, but only to a point. Years ago the V8 was a much better choice, but not today. Three of four Mustangs sold originally were V8, which now makes the 6 a more rare choice. One of the Mustang books about 15 years ago listed the 6 as $900.00 less value than the V8, but if the 6 has AC, the value is the same. After I got my 6 Pony I got serious about it and have found much to be said positive about the six. If you plan to upgrade the car no matter the engine, all the special parts are also available for the 6 powered car. I have added front discs, a rear anti-sway bar, polymer bushings in many places, and new rubber bushings in all others, stiffer front coils (cut 3/4 turn), V8 rear leafs (115 lbs compared to 85 lbs), gas shocks at all 4 corners, 15" x 6" wider wheels/tires, and 1" lowering blocks in rear. The V8 adds about 250 pounds to the front of the car, plus 50 lbs. in other places. That makes it front heavy, while the 6 cylinder is much better balanced front-to-rear. With a maximum bigger bore, mild cam, 2-barrel carb, hotter ignition, and better exhaust, the car runs much faster than any US speed limit at well over 100 mph, can canyon-carve with many sports cars, rides nice and gets 25 mpg on the highway. Mine has AC and a modern stereo system, new tinted windshield and many extras. It is a driver I take on long trips and I have never missed not having a V8.