This Carb spacer didn’t work for me, but might for you

[Killer6]

Oh, boy...........

 

[Dave999]

Were they trying to level the carbs? Some V engine manifold carb bases are tilted

well with 2 or 3 DCOE carbs side by side, regardless of if the throttle shafts are supposed to be coupled together, or if you will activate each carb via an individual drop link from a cross bar linkage. it is imperative that all carbs sit in the same plane. the 6 top studs and the 6 bottom studs for a 3 carb set up on an inline six should be perfectly inline so that all carbs when correctly bolted down and synchronised open at the same rate
any mismatch leads to a mismatch in throttle opening distance and the rate of opening to achieve that open distance..

advice from most weber places is is the carbs are not aligned send the manifold back or get it welded and re drilled correctly.

i don't mind if the carbs are angled up or down within operating tolerance
in fact machining the inlet/exhaust gasket face on an angle with an aim of straightening access to inlet port and exit for exhaust gas may be a trick that would work i.e alleviating some of the near 90* short turn down to the back of the valves in the port.

but standing at the fender- having the 2 end carbs horizontal with the middle one at a a couple of degrees anti clockwise angle is just WRONG especially when it is the one where the throttle shaft is supposed to be directly coupled to it neighbour..

align the studs for the carbs, i'll worry about porting the manifold to the carb gasket should it be necessary..... etc