Weber WFB Carb tweaking for engine update

[NHGuy]

I'm doing a 383 for my boat this winter and I've just started to really look into whether I can keep my Weber. It's the 9781 model. At the RPMs I will run it's got the perfect amount of CFM.
I'd like to tune the carb for the bigger motor.
Here's where I am stumped right now. The metering rods are 3 step in the Mercruiser Weber carbs. And they are 2 step in the Carters, Edelbrocks and the old style Webers... Which are all from the same family.
The Mercruiser Weber uses a taller cover, different pistons, tall different jets and the 3 step rods. That I understand.
I have found some standard tops, jets, pistons and springs from Edelbrock. What concerns me is will the Edelbrock pistons work in the Weber casting?
It looks like they will. Have any of you done this?

 

[Bondo]

Ayuh,..... 1st off, This is the bible for these carbs, Lotsa Great readin' in there,....

Along with one of these "Kits", you can tune that carb to run on yer motor, No problem,....

I changed the needles, 'n springs in mine, didn't need to change the jets,...
I also just used the pistons that were in the carb,....

 

[NHGuy]

Nice! I know you have said before that it's do-able. Thanks for the links. I will work them into my learning an planning