From what I've heard you need push rods, Crane sells them I think they are a little longer. But some people have had luck with the stock push rods.
T-bolt use some 351W heads on a 68 302 and he used the stock push rod's and he took every valve guide out of the heads.
If you can find the early 351W heads 68-70 they have the 1.84 and 1.54 valves and 60cc chambers.
If you already have the heads, you should probably CC the chamber to see what you have. You would likely lose power if you drop the compression much. If they are big, you could have them milled at a shop for not too much dough. The 351W heads are machined for 1/2 inch head bolts, and the 289 uses 7/16. ARP supposedly makes spacers for the heads so you can use 7/16 bolts or studs.
If you already have the 351W heads (C9OE or D0OE are best) and intend to replace the pistons or have the heads shaved, then I'd say do it. Otherwise, if you have some 289/302 heads with the small chambers just home port and put in the 184/154 valves.
Depending on the deck height of the block and the pistons you use, compression may drop with the 351W heads. Back in the day, the Ford factory kit for this 289/302 mod included pop up pistons to maintain the higher compression.
I've seen dyno #'s on similiar engines. One had 302 4V heads with home porting and the bigger valves. The other had the 351W heads. Numbers were about the same for power on both engines.
I'll sell you the 351 heads that are on my 289 now that have 194 160 in them. With them and a cam of about .52 lift my falcon ran 12.70 with a 4 speed and 456 posi. Or sell you the whole 289 it has the head bolts drilled and tapped to 1/2 13 so no spacers needed.
Well actually im building a 351w but it will take a little time and i was thinking if it was no major ordeal or if it would bennifit me to use those heads on my 289 for now. My best bet i think after the responces is to just do the 289 heads and save my 351w heads for the rebuild. Thanks for all your opinions all!