I do like e-85 very much the more I use it. This fuel requires about 27-32% more fuel for the same amount of air. From volume to main jets. This is a big reason my car is taking EVEN LONGER to get out to the races.... Been giving me a lot of headaches along the way. That said, the fuel is very forgiving and appears to let you go "lean" without melting plugs/parts.
The modifications to my webers is immense compared to a stock 48. Lot of trouble not only getting the fuel TO the carb but getting it from the bowl to the jet to the venturi.
My engine is probably at the limit of using a 48(mine are 52) as far as hp is concernd with the bowl capicity being the main restriction. I recently upgraded to a full Magnafuel system with all new line and regulators and I was still having trouble getting fuel to the bowl (needle and seat being the restriction). I am working on a new N/S idea to save a lot of headaches for future vw weber racers at the moment.