Originally Posted by FurryStump
Originally Posted by Sniper
Originally Posted by FurryStump
Unless you have the 727, I would go 904, it would need a different driveshaft than the 727, but I would not put a 727 behind a small block. I just changed from a 727 to a 904 and all said and done will have picked up 2.5 to 3 tenths. Now, I increased my flash rpm by 300, in the same dia converter. Both were PTC 9.5” converters. I also changed to the low gear set inside the 904. I also went aluminum for the driveshaft. So it is not just your typical 727 to 904 swap, but no more 727’s for me. Just not necessary. As an added benefit a much lower risk of shattering the drum.


This isn't the race forum and no asked about picking up a tenth.


True, but he’s running headers so he probably isn’t a restoration/date code/part number guy. If he has nothing on hand there is no reason to run a 727, except if he cares that it might have come with one originally. Racing or not, do you want to run a less efficient transmission? More power to the wheels, better mileage, safer, comparable cost. Valuable info no matter what you are doing with the car.


So what? The 727 is more than sufficient to handle a 340. The same cannot be said about a stock 904. Safer? Not stock it ain't. Comparable cost? Not finished it isn't. maybe a core to build is comparable in cost but a stock 727 is all that is needed to handle the load, a 904 needs lots of costly parts to do the same. To be honest, if I was going to make the mistake of putting an automatic in place of a stick it wouldn't be either the 727 or 904 varieties. I'd get one with an OD gear.