I went the same route. Had a 557 with the same heads. Broke it and built a 588 with A 460 heads. Sold the car complete with the 588 and now I'm gathering parts for a new 598.
You will need new pistons for the A460 heads. The valve reliefs are totally different.
The headers will work with the new style Trick Flow A460 heads as both have BBC spacing. I used the same ones. If you were to use an old set of Ford Motorsport A460 heads they will work if the headers have individual flanges for each cylinder. The old heads have a BBC flange, but the spacing is slightly different. A one piece flange won't work, but you can cut them to make up the difference.
You will need new pistons for the A460 heads. The valve reliefs are totally different.
The headers will work with the new style Trick Flow A460 heads as both have BBC spacing. I used the same ones. If you were to use an old set of Ford Motorsport A460 heads they will work if the headers have individual flanges for each cylinder. The old heads have a BBC flange, but the spacing is slightly different. A one piece flange won't work, but you can cut them to make up the difference.