Camshaft for 289 A Code

You can put what ever cam in it you want, just keep in mind that anything more than around a .500 inch lift will require an adjustable valve train, and maybe a new torque converter and rear gears as well, to take full advantage of the cam.
If you don't have ready access to a machine shop, I'd recommend staying under .500 lift...

Ditto on what woodsnake said. You're looking for what's called an "RV" style grind. The @.050 specs will be in the 200-214* range and lifts no more than about .510 lift. Comp Cams 268H is a good pic, but you may need to run premium fuel with it. Summit Racing sells a cam in their own brand that specs at 204/214 and .448/.472 lift that'll work, Also the next step up may work with the stock heads ( 218/228* .471/.471 lift) Anything more and you'll have the stock pressed in studs pulling loose from the heads.

Go download CamQuest (FREE) off of the Comp Cams website. It will tell you a recommended cam for said application.