berg special 42 dcnf carbs

[bean]

anyone used them?
came fitted to my latest ride and was after some thoughts on them performance wise.
1776cc
AS 41 case. Duel oil relief
043 magnum heads ported and polished & welded for additional strength
dual valve springs & long reach plugs.
Valves : 42 x 37.5
Custom valve guides
Rimco super rods
120 Engle cam
Straight cut cam gears
Counterweighted Crank
Lightened flywheel
Burg deep sump
Full flow oil system with remote HP1 filter and mesa cooler Burg
equaliser pulley "Berg Special" Weber 42 DCNF carbs with burg linkage
Burg Stinger II electric ignition Thunderbird merged header with twin
quiet pack

dual quiet pack is going and was wondering what the next limiting factor would be.