The above posts are Correct, "BUT" if you started out with Marine carbs, and then switch to Lets say Hollys all you need to do is switch the Green marine tag to the new holly and BINGO the Inspectors willnot catch you.
PROOF!!!! I had a pair of Rodchester Quar-Ra-poopies, switched to Holly 650s painted everything MERC black and switched Tags. Got stopped and Inspected due to Thru-HULL exhaust [ stock Merc 4"] by a pair of Local wanta be COPS. They looked at and searched everything.
I don't say Break the Law BUT!!!!
The new Webber carbs are the old CARTER AFBs