Car bogging down a bit

I swapped my 34 Pict 6 carb out for a 31 pict 6 the other day and swapped over what jets i could and gaskets etc. and it seems to run fairly well. It idles well and when youre driving most of the time at a consistent throttle its perfect. But there seems to be an issue of bogging down (sometimes quite badly) particularly when the revs are low and on acceleration. It can even be so bad that i cant pull away so have to press the clutch build the revs up higher and then itll be fine. There is also some occasions where if im going at a steady speed and want to accelerate itll bog for the first bit of throttle then at a certain point it will be fine and pick up well and accelerate.

Im not sure if it is an under or over fueling issue? and it seems to have gotten worse. There is one jet which im not sure if it needs to be larger or smaller and also i couldnt remove the cover for some of the diaphragms to replace. I have a suspicion there could be some form of blockage but I think the symptoms would be much worse if that was the case.

Any help would be greatly appreciated,

Cheers,
Matt