i was thinking for bench pressing and incline db press.
I know it's not illegal, but unfortunately neither is doing 50 reps with 5kg on that pulldown machine as I see many people.
I know that 5x5 is for strength but a bit more volume is needed for bodybuilding, I was just wondering if it's likely to get any results if only change my bench exercises and leave the rest as it is now.
It would depends, what results are you after? what are you trying to achieve?