Annular vs downleg boosters on carb

You can still buy at least 3 different sized “950’s”.

The original HP950- 1.375 x 1.750
QFT style 950- 1.450 x 1.750
Holley XP950- 1.600 x 1.750

My “good” 4150 carb I had done 30 years ago by Norm at CFS.
HP carbs didn’t exist yet, so modified std bodies were the way it was done.
I sent him a new Holley 4781(850DP), and he worked it over and swapped out the boosters for annulars.
It’s been a great carb.