Pontiac
Catalina Super Duty 421 'Swiss Cheese'

Why it matters

The 'Swiss Cheese' Catalina is the most extreme of the factory lightweight Super Duty Pontiacs built to win in NHRA Super/Stock drag racing. Pontiac cut the frame full of holes and used aluminium panels to take weight out, and only 14 cars were built before General Motors' ban on factory racing support.

How rare is it?

Six separate kinds of rarity – never combined into one number.

Each kind of rarity is rated separately and never combined.

Production

Every figure says what it counts.

Independent counts (e.g. engine and colour) are never combined into a calculated figure. Surviving examples are never presented as original production.

History

By the end of the 1962 drag season Ford, Chrysler and Chevrolet were catching up with Pontiac in Super/Stock, so Pontiac's engineers developed a lighter and more powerful Catalina for 1963. GM issued a corporate edict on 24 January 1963 that ended racing activities, and the Swiss Cheese cars were built before the ban. The last one, built on 2 April 1963, was ordered by Pontiac Engineering for 'internal research' and was painted Silvermist Gray rather than the usual Silver Fire-Frost.

One well-known car, sponsored by Packer Pontiac in Detroit, was driven by employee Howard Maselles to the NHRA C/Stock record of 114.64 mph in 12.27 seconds, which stood for several years. Racer Mickey Thompson ended up with two of the 14 cars.

Technical specifications

Engine

Transmission & drivetrain

Chassis, body & dimensions

Performance

“Not yet verified” means no source has been checked for that value yet. Nothing is estimated to fill a gap.

Identification guide

How to tell an original from a replica or later conversion.

The frame is the main identifier: the inside of the boxed rails was cut away to leave a U-section, and about 120 holes were drilled in the rail sides (Silodrome says about 130). The cars use aluminium hood, inner and outer front fenders, splash pan, radiator bulkhead and bumpers, aluminium bellhousing and differential housing, high-flow aluminium exhaust manifolds with integral cutouts, and no front sway bar. Most cars were Silver Fire-Frost. The 421 has 13.0:1 Mickey Thompson pistons, a number 10 McKellar camshaft and dual Carter AFB four-barrels on an aluminium manifold.

Sources

Each number links to the exact facts it supports.

1. 1
   SD-421 Super-Duty Pontiac: Lightweight Heavyweight! Level B Car Guy Chronicles

   • one of 14 factory built
   • 13.0-to-1 Mickey Thompson pistons
   • a #10 McKellar camshaft, lightweight valves, reworked heads
   • Dual Carter AFB four-barrels on a special aluminum manifold
   • Rated at 410 horsepower
   • originally equipped with Borg-Warner three-speeds with aluminum tail sections
   • aluminum-case 4.30-to-1 Posi differentials. Most were converted
   • cutting the inside section away from the boxed rails, leaving a U-shaped section
   • deleting the front sway bar
   • car's 3,308-pound shipping weight

   Accessed 2026-11-12
2. 2
   Mac's Motor City Garage – Secrets of the 1963 Swiss Cheese Pontiacs Level C

   • 14 Swiss Cheese Catalinas built by Pontiac ("Only 14 ... were built", nine said to survive)

   Accessed 2026-11-12
3. 3
   Pontiac Catalina 'Swiss Cheese' Super Duty Level B Silodrome

   • 421 Super Duty V8, a 6.9 litre engine
   • aluminium alloy fenders, inner panels, both bumpers and an aluminium hood

   Accessed 2026-11-12
4. 4
   Mickey Thompson's Pontiac Catalina Super Duty headed to auction Level C GM Authority · 2025-05-01

   • 410-horsepower beast
   • Rear gears were either 4.56 or 4.88

   Accessed 2026-11-12