You can stroke a 289 up to a 428! 302 and 289 both have a 4.000" bore. If you want to stay with the 4.000" bore you can go up to a 416ci. That takes a 6.2" rod. In order to get to the 428 you need a 4.128" bore and 6.49" rod.
I once read in a magazine article that it's not even a good idea to out a 302 crank into a 289 block. The reason being: a 302 block although similar in size has a larger "lip" (the bottom of the cylinder wall) to accomodate the extra stroke. I would not attempt it, because a 347 stroker crank is made for a 302 block, and the piston may "come out" at the bottom of a 289 cylinder. Just my two cents.
Coast High Performance offers a 347 stoke kit with altered wrist pin location to avoid the ring land intrusion common to stroke kits. I personally am finishing up a 289/347 stroke kit (Bored .04 over) from Eagle and have no problems with cylinder lip or bottom end clearances.
I've read and saw a picture on another site about a year or so ago. That differnence in overall lenght of the 289 vs. a 302 appears to be a falasy. However, accordind to Ford blueprints, shows a difference. This appears to be a case of "as drawn" and "as built" and anybody who works with blueprints knows this all to well!
Methinks you have confused a 302 with a 351. A 347 kit is the largest made for a SBF. I have also read the warning about stroking 289s and have also seen information that it is OK. I'd contact the kit manufacturer and talk to someone there that is knowledgable, and I'd take anything they said with a grain of salt, before I actually tried it. And the bad part is you might not know when you were done. If the piston skirt is dropping out of the bore is that a problem or not (assuming it isn't hitting the crank). Beats me. Build 30 of them, run them for 100,000 miles and get back to us.
In the meantime I'd spring the extra couple hundred bucks and get a new roller block from Summit.