I would stick with a 904 in an Early A. The 727 usually needs to "clearanced" with a grinder or hammer to fit an Early A, not worth the extra tightness and goobering up your Early A. But you will need a 66 or 67 V8 904 or use what you have if you buy the 65. You should be able to find a driveshaft used to fit. If you do the swap, get it running as soon as you can. Much easier to keep engaged when your car runs.
