727 vs 904

Engine to trans braces are the same, 904 to 727. The kickdown lever is also the same, being car specific. The A bodies, and the B Bodies 66-70 use the 3 pc bellcrank setup. E Bodies, B Bodies 71 up and C Bodies use the one pc rod setup. The 3 pc bellcrank system use the shorter kickdown lever, where as the one pc rod uses the long kickdown lever. There are slight variations in both levers. Also Dodge pickups always used the 3 pc bellcrank systems. Also the shift lever is your car specific.
For example, a 68 318 dart with a 904, swap to a 727- use your 904 kickdown lever and shift lever. Everything should be fine. If the car is a column shift, the Z bar is different between the 727 and the 904. I'm the guy that will never use a cable kickdown setup. I have boxes of stock linkages that I cut up and modify. I've probably fixed 25-30 peoples kickdown linkages with my parts. I tell the people, my setups won't be 100% factory and 95 % of the Chevy guys won't know that it's been fabricated. And they all work like they are supposed to.