Among the collection of classic Ferraris that will no doubt litter the auctions coinciding with Monterey Car Week this year will be two examples of a particularly rare Ferrari, the 275 GTB/6C Alloy.

An unrestored 1965 example finished in red will go under the hammer at the RM Sotheby's auction, while a 1966 example in yellow will be sold at the Mecum auction.

The Ferrari 275 GTB made its debut at the 1964 Paris auto show, initially with a 3.3-liter V-12. It was Ferrari's first road car equipped with a transaxle and independent rear suspension, and it proved popular for both grand touring and racing.

The cars going up for auction feature the long-nose body by Scaglietti that Ferrari introduced in mid-1965 to reduce front lift at high speeds. They each also feature six carburetors and a lightweight alloy body designed for racing, hence the “6C” and "Alloy" designations in their names.

The red car, which bears chassis number 07809, is claimed in its listing to be the third of the long-nose 275 GTBs and the example displayed by Ferrari at the 1965 Turin auto show. It was initially purchased by privateer racer Luciano Conti and, among its campaigns, saw action at the 1966 Targa Florio. It raced under the number 228 but completed just two laps before it was forced to retire.

1965 Ferrari 275 GTB/6C Alloy bearing chassis no. 07809 - Photo credit: RM Sotheby's

1965 Ferrari 275 GTB/6C Alloy bearing chassis no. 07809 - Photo credit: RM Sotheby's

Conti, who was also the publisher of the magazine “Autosprint,” in which Enzo Ferrari penned several articles, eventually sold the car in 1966. It then traded hands multiple times, including at one point to Glickenhaus Racing founder and Ferrari collector James Glickenhaus.

The yellow example, which bears chassis number 08157, was originally sold to Pirelli, which used it for tire testing from 1966 to 1968. It features unique rear fender flares, believed to have been added by Pirelli to fit wider tires for testing. A photograph of it taken at a Pirelli test track was published in L.J.K. Setright’s “Ferrari” book.

After its days of tire testing were over, it was sold to Pietro Achilli in 1968. It then traded hands multiple times before its current owner purchased it in the mid-1990s. It was painted yellow during a restoration by the previous owner.

In both cases the bidding will likely reach multiple millions.

This year's Monterey Car Week starts August 11 and runs until August 20, culminating with the Pebble Beach Concours d'Elegance.