From two feet away, a titanium carb looks just like the standard Holley. And, NASCAR uses air gauges to check each carb at the track---so dimensionally they are probably the same as a Holley. The difference is weight.

I never knew there was such a thing until about 5 years ago. Here is the story. We were racing dirt super late models then. After Tony Stewart bought Eldora Speedway, the Nascar stars began running the "Prelude to the Dream" race program. The Nascar stars actually borrowed the late models to run. Our former crew chief was the crew chief for Bill Elliot for that race. Bill flipped his car down the straight and the carb was destroyed. On the return trip, they stopped at our shop and our former crew chief shouted at my son and tossed the carb to him. Expecting to catch a six pound carb---he was amazed it weighed less the two pounds. That's when we learned about the carbs.

How much is a lower center of gravity of four pounds worth?