@EV Dabura called him the perfect fighter and was confident he would do a better job than him. Furthermore, Vegeta treated Dabura like trash and wasn't contradicted by Goku, who was surprised when Vegeta revealed he can turn SSJ2.
Goku says he needs to get enraged to beat everyone, while Gohan says he needs to go full power to rival Buu. Clearly are different things.
If they were SSJ2 tier Dabura blast would have wounded Gohan, unless Gohan is much stronger, what doesn't seem to be the case.
@FW isn't Daizenshuu 7 about anime? Daizenshuu 2 also lacks a + on SSJ2 Gohan's appearence, implying he was only SSJ2 on Vol. 37, whilst Gohan fought Dabura on Vol. 38.