I've never touched a weber.
And I've never had a float blow up on me in a standard carbie but thats cause I've always put solid ones.
My friends that got me onto boosted A series engines always warned me though.
They told me stories of the floats blowing up on them, they said its the loudest bang you would ever hear and you #### your self cause at the same time the car floods and dies. I couldnt say how much boost you could safely run without it happening but I wouldnt run more than 10 psi, and who knows how strong a webber float is.
Isn't there a bloke on here from Tas with a blowthough webber setup in a 1000 wagon? maybe he could tell of his experiences.