The head can handle it,. the legs will be a stretch.
However, ballheads are not great for long lenses on their own. Add a sidekick (Wimberley) and your in business.
The legs look to be "series 2" but I don't know if Sirui follows the same "Series" conventions as Gitzo and those that mimic Gitzo, like Induro and Leofoto. If they do, they aren't the best legs, series 3 or 4 would be better, but I have used my Series 2 Systematic legs made by Induro with my 500mm when I wanted something more portable, and it was fine. Those however were rated for 44 pounds, and it looks like Sirui is rating your legs at 33,. so indeed, not all series 2 are made alike.