This is a bit dated information, but I figured some people might not have known about the change. 49ers defensive end/tight end Demarcus Dobbs changed his number to 83 and Will Tukuafu changed his number to 48. Dobbs wore 96 last season before switching to 40 during training camp. He made the switch to 83 in late August. Tukuafu made the switch from 92 to 48 prior to the Giants game.
In switching out from their numbers in the 90s, Dobbs and Tukuafu are able to play on the offensive side of the ball without declaring themselves eligible with the officials. Given the frequency with which the 49ers use heavy sets and Tukuafu at fullback, teams are already preparing for these formations. Nonetheless, not having to vocalize to the world that the team is bringing in either is always a perk.
Tukuafu has brought some serious skills as a blocker. The 49ers primarily used Isaac Sopoaga in this big fullback role last season, but Tukuafu has taken control of the role this season. It's safe to say he is doing a strong job in the role thus far.