Used, Performance Option part, shown in the Alfa Romeo Catalog, Carb side is 40mm , the lead opening does have chamfer and the head side roughly 37 x 48mm opening. $500.00 usd. and the costs to ship or mail.

Automotive exterior Material property Rectangle Bumper Gas
Purple Wood Auto part Magenta Metal
Wood Natural material Metal Magenta Titanium
Purple Gesture Pink Violet Red
Backsaw Tool Magenta Font Metal