Centerline custom built parts are usually good and in the case of the Weber bellcrank better than the original. I am surprised that the support rod did not fit.
My intake manifold is raised compared with a stock one and I "made" a support by cutting and welding a stock one. It is jobs like that that make wrenching my Alfa's more interesting.
OTOH it is sad that a lot of aftermarket parts are of much lower quality than OEM but that is something we have to live with when we drive old cars that were produced in low numbers. The situation is not helped when many Alfa owners buy the cheapest parts that they can find and kill the market for better parts that would be more expensive to produce,
76 Suzuki GT500
2011 Jaguar XKR
A little government and a little luck are necessary in life, but only a fool trusts either of them. - P.J. O'Rourke