Weber Adaptor 2 x IDF to 4BBL Holley - Part # 12-3143 Weber Adaptor 2 x IDF to 4BBL Holley - Part # 12-3143 Carburettor Adaptor Plate to suit 40mm, 44mm & 48mm IDF Weber Type Carburettor to suit all V8 Squarebore manifolds. This was a very popular Group C racing package and... MSRP: Was: Now: $479.00 Add to Cart