Just about everyone has covered it,i think without realising it.It's all about tuning.The biggest problem in Australia at least is that there are bugger all people left (oldies) that have dyno's and a few thousand dollars worth of jets sitting in a corner of their workshop and with the knowledge to extract all there is to be had from Webbers.I speak from personal experiance,we use twin 45's on the racing car and have great difficulty finding people yo get them right.On the other hand EFI still requires a dyno but all you need is a lap top and be able to read the information the dyno sends you then make the appropriate changes to set up to get a good result.