Hesitating

[Belgium R/T -68]

Changed the carb on my GTX 440 from a 600 to a 750 and now it starts to hesitate when I give full throttle. The carb is new and with the 600 it ran good.
Could it be that I have to adjust the timing since I don't set it with the lamp but via feeling? 

[aifilaw]

If you never touched your timing, you probably shouldn't mess with it yet.
If you have vacuum secondaries you may need to change your spring for when they come in, that will cause hesitation, same with the jetting of the carb.

[Chryco Psycho]

you have a bigger carb & it hesitates when you floor it because the vacuum drops more , so you either need more fuel with the accelerator pump or more timing , or both to overcome the bog