It will add OD to your 904. AND, you can use it in a way that you toggle in and out of the OD unit as you are upshifting. (It's tricky to learn, cool when you do). So, I apologize if I confused you. What were the questions?
im not actually sure! haha. so in the end would it be worth the cash to add and overdrive to a 360/904 combo? the car is gonna be a daily driver with 280hp and i just want it to get the best mileage possible. my understanding is basically the more gears, the high fuel economy. so overdrive would work like a 4th gear. thats why i was excited about this product, it allows me to have a 4spd automatic and allow me to get better fuel economy.
is there a cheaper way to put an overdrive onto my 904 without hackin, slicing and cuttin? if there is id love to know it, and so would my buddy Rick (hemiram2006) since he may want to do overdrive on his 727