Before the GM Brass could put a stop to the competitive motorsports involvement of the various brands that were either overtly or covertly supporting those activities, Pontiac was trying to keep their position atop the drag racing podium. Ford, MOPAR, and Chevy were all nipping at Pontiac’s heels, and something radical would have to be done to continue their domination of NHRA racing. When it came to reducing weight on the Pontiac Catalina competition cars, the ideas were more than unconventional.
The Excitement Division would build fourteen Pontiac Catalina “Swiss Cheese” cars before GM enforced the AMA ban on factory supported racing. To trim weight, the engineers at Pontiac trimmed off the top of the boxed frame creating a u-shaped channel, then cut around 120 holes in the remaining frame sidewalls, removing as much steel as possible while still retaining some hint of structural rigidity. However, the weight saving efforts didn’t end there. Many steel body panels were replaced with aluminum including the inner fenders, front outer fenders, splash pan, radiator bulkhead, bumpers, and brackets. Much of the glass was replaced by Plexiglas, the front sway bar was eliminated, the iron exhaust manifolds were replaced by aluminum units with integrated exhaust cut-outs that could only be used for short periods of time lest they melt. The battery was moved from the engine compartment to the trunk, and all unnecessary body sealant and soundproofing was removed.
In order to give the Pontiac Catalina more power, the Super Duty 421 received Mickey Thompson 13.0:1 compression pistons, a McKellar cam, reworked heads with lightweight valves, a heavy-duty crank and lightweight flywheel. Dual Carter AFB carbs sat atop an aluminum intake. Some of the cars retained Borg Warner three-speed manual gearboxes, but others swapped to the close-ratio four-speed box. Rear gears were either 4.56 or 4.88 in aluminum housings. The result was a 410-horsepower beast that could run the quarter-mile in the twelve-second range at 120 miles per hour.
Two of the fourteen Swiss Cheese Pontiac Catalinas wound up in the hands of racer Mickey Thompson. Our feature car, finished in Firefrost Silver over a tri-color blue vinyl and cloth interior, is one of those cars. It was raced extensively in period on the west coast. It has been the subject of a comprehensive restoration at the hands of Scott Tiemann of Supercar Specialties. The Catalina is powered by its original 421 Super Duty backed by a three-speed manual transmission. Included in the sale is a binder with photos of the restoration and Pontiac Historical Society paperwork.
Comments
Mickey Thompson had his hands in everything motor sports. He was the Man.
Ever seen Malcolm McKellar’s SOHC Pontiac 421?
How can you not like full size 421 poncho’s
I want to see pictures of the swiss cheese underside.
A lot of folks were building light weight stuff, but hadn’t heard of Swiss Cheesing the frame. That SOHC 421 V-8 interesting. Probably the most interesting Pontiac V-8 I ever saw personally was a Ram Air V.