In the early 1950s the “street” cars used three of the two-barrel Weber carburetors. The air cleaner assemblies were supplied by F.I.S.P.A with a small aluminum F.I.S.P.A tag riveted to the tops. Two-Barrel early regtangular F.I.S.P.A air cleaner tag.
The late 275 GTB/4s and 330s used a new type air cleaner assembly with four “snouts” on the sides replacing the perforated steel side panels. These air cleaners used a large rectangular blue F.I.S.P.A tag. These are 92x35mm with 67mm hole spacing. These and all of the earlier tags are attached with small aluminum or steel round-headed hand-bucked rivets. The very early tags on the “Ram’s horn” castings were attached with “U-drive” or “Drive screw” type fasteners. Rectangular F.I.S.P.A air cleaner tag for 275/330/365s
The later 275 and 330 desings reverted to the crescent-shaped aluminum tags as had been used on the earlier inside-plug 250 cars. The filter element number that is stamped in the “Tipo” block on the tags has changed from “AT4094” on the inside plug 250s to “2228.01” for the 275/330s. 275/330 crescent-shaped air cleaner tag.