Depends on what it needs. First off a 67 904 isn't the best to build on. It has the smaller input shaft and the converter will have to be specially built to mate up the larger diameter crankshaft register that 68 and newer engines used.
I'm all for using a 904 too, just find a newer one. I'm not a 904 guru but have rear 72 and newer are the better ones to build on. Just watch out that you don't get a lock up trans.
