Plan on about $3500 to $4,000 to convert to a 4 speed. I have a 69 340 Fastback Barracuda that used to be a floor shift automatic, but I wanted a 4 speed. I got REALLY lucky and found a rough but running 340 4 speed 69 Barracuda fastback with a console and ALL necessary (and correct) 4 speed parts. I pulled all the 4 speed stuff, and by the time I parted out the rest of the donor can, and sold my perfectly good 727 and console, I made money on the deal. But unless you get really lucky, it will cost you. Plus you have to weld in a 4 speed hump. Brewer's performance has EVERYTHING you need and they are wonderful to work with. The actual conversion is not too difficult. A competent shade tree mechanic can co it in a few weekends.