The TQ is one of the most overlooked carbs in the muscle car world. I have used one of these on a Mopar m1 intake on my 512 stroker since 2008. I did the needle and seat mod as mentioned in your post. The only problem I have ever had with the carb is that it has leaked fuel around the gasket on the top rear corners of the plastic fuel bowl. There is an area in the corners where the plastic will warp (After about 50 years of heat cycles) from the pressure being exerted on it from the clamping pressure of the fuel bowl cover. The corners of the bowl had yielded about .005 of an inch. I corrected the warpage with a thin of application of JB weld epoxy around the rear corners of the bowl mating surfaces and then sanded it down level with a good flat metal sanding block. This has been a durable repair and has held up for about 4 years now. My engine runs very well with this carb and gets better than average fuel mileage for an engine of this type. I have never seen any reason to switch to one of the ubiquitous Holleys.