I recently spoke with Mike Suter as a pair of his ‘reproduction’ dual quad Teapots were being run as part of the dual quad intake test. These two carbs had been pre-run before being delivered here for testing. He was instrumental in doing some over the phone troubleshooting on the Teapot carbs in general and I found that he is indeed very knowledgeable regarding the Holley model 4000 carbs. On the ‘reproduction’ Teapots that were being used, the power valves themselves were replaced during the testing with ‘larger’ units rather than increasing the jet sizes. This kept cruise A/F ratios acceptable so that the fuel mileage would not be compromised but at the same time, full throttle A/F ratios could be maintained in a richer mode for more power production.
Here’s another link where he’s also being recommended.
http://www.y-blocksforever.com/forums/Topic78379-3-2.aspx#bm78632