The Trans Am 421 SD - Transcendental Transformation

HPP: How is the Shaker made functional?
KW: The base of the Shaker was fabricated by our GM Performance Division to duct the air forward to the throttle body.

HPP: The 421 SD T/A also has a blue interior, an obvious heritage clue.
KW: My '71 T/A had a blue interior, which a lot of them did. I wanted to keep the 421 SD T/A true to that as well, but instead of Morrokide like mine had in '71, we utilized leather on the show car.

HPP: Are there any more heritage interior cues on the 421 SD T/A?
KW: Yes. I made a machine-turned appliqu on the instrument panel and used a modern-interpretation of the classic Formula wheel.

HPP: How much of the 421 SD is custom fabrication and how much is off-the-shelf parts?
KW: All of the design cues were remodeled in proportion to work with the new body. And it wasn't as simple as just getting the parts and putting them in the car. We actually went through the exercise of remodeling the car.

HPP: We know that GM hasn't had Pontiac engine blocks, especially vintage 421 SD blocks, in decades. What's really under the hood of the 421 SD T/A?
KW: The engine was the new breed, a Ram Air VI C5.R motor that Katech put together. The company did all of our race motors for our Cadillac CTS-VR and the Corvette Le Mans race cars. So we tried to mix a little bit of the new technology with the old heritage.

HPP: How much horsepower does it put out?
KW: That's 580 hp at the crank.

HPP: Given the fact that this is primarily a show car, were the transmission and rearend upgraded to handle the power?
KW: The 4L60E automatic trans was prepared for the extra torque of the 421 engine, and the stock 10-bolt rearend was replaced with a 12-bolt DTS unit with 3.42 gears.

HPP: What were the comments within GM on the 421 SD T/A?
KW: I think a lot of people really respect the heritage of the Trans Am. My memory says everybody liked the car.

HPP: Bill Porter was the director of design on the Second-Gen Trans Am. Did he share his thoughts on the 421 SD T/A?
KW: Porter was one of my mentors. I had him as an instructor when I was in college. He was a fine designer, and I remember him telling me that all the stuff on the 421 SD Trans Am was functionally correct.

HPP: Can you describe to us how you felt when you realized that the 421 SD T/A was just as fun to drive as your '71 Trans Am 455 H.O.?
KW: I was driving up to Fort Riley, Kansas, and I remember racing a Mercedes on one of those interstates out in the middle of nowhere. I was amazed at how the 421 SD Trans Am, at a very high speed, sucked down. You could really feel the air dam in the front and the spoiler working to make the car very stable. That was the thing I liked about those original Trans Ams-those spoilers, those spats, those Shaker scoops-they were all functional items, not just styling gimmicks. I thought that was pretty significant.

HPP: Were you able to get a performance comparison between a '71 455 H.O. and the 421 SD T/A?
KW: No, we weren't, but I'll tell you: That would be an interesting test, because my '71 T/A still exists. I can assure you from a chassis standpoint, that 421 SD T/A is probably better. The 0-60 mph, however, would be an interesting race. I remember the 455 H.O. I had was very fast, but I would guess the 421 SD T/A with the Katech motor is probably faster [laughter].

HPP: Mr. Wasenko, thank you for your time. I have one last question. Should the '03 Trans Am 421 SD have been produced for dealers?
KW: I loved that Trans Am so much, and I really felt that we should have tried to do a heritage-type car. It was a disappointment that we didn't produce it.