If anyone has a set of old Riva Powerbombs you have a set of DASA carbs in your hands...they are nearlyidentical. We tested between Novi, Riva/DASA, and Full Spec on the same Race gas/total loss/PFP billet 898 and ski and liked them in that respective order. Like Phil said, you really are splitting hairs between the best carbs. They all work great. To be fair and forthcoming for the Full Specs we did have a set of their new freestyle 49's which have a large venture restrictor above the 49mm butterfly to help boost signal. This necks the 49's down to somewhere near a 45mm. You could feel this carb did a better, cleaner job metering fuel at low throttle levels than the other two carbs but also didn't deliver as much air as the other straight through 48mm carbs did at WOT. Again, anyone may find their particular engine setup may prefer a particular carb this is just what we found on our fw setup.