Well a carb is a carb is a carb
So there is no reason why you can not put another one on your engine.
You could fit a 4 barrel Holly if you really want to
However you will need to make up an adapter plate and then lengthen the control rods.
If you like to tinker then go ahead but it won't be cheap.
If you want to see what might be available as a bolt on then have a look at the racing mower specialist supply shops.
As you go up in grades then special carbs are permitted.
Almost any motorcycle carb can be made to fit or if you want to spend money there are lots of bolt on Tillotsens.
However you will be breaking EPA regulations so could be subject harsh treatment from narrow minded enforcement officers who really believe they are saving life on the planet.