They're not the carbs that came with the car, if that's what you're asking. They are a pretty standard replacement for the original Zeniths/Solexes that have a bad rap for being difficult to keep tuned. Trouble is, the total throat opening is smaller than the Zeniths, so things can get a little flat over 4000 rpms. One of my E9's came with DGAV's, and though they run fine, they lack the punch of the Zeniths. At the moment I'm looking into alternatives, such as syncronous 38/38's. There are folks on this board with triple 40's or 45's but IMHO, it's a bit too much CFM for a street motor. (what kind of choke does my car have)