I've installed a 10" dirty dog converter in my 97 4.6L TBird and the 60ft and 330ft is 2 to 3 tenths quicker than before but is slower after the 1/8 mile. The 1/4 mile speed is slow by 5mph and a couple tenths slower on et. I changed plugs and maf sensor and verified good fuel pressure. It took a couple trips to the strip to discover the 1-2 shift is earlier but the 2-3 shift is later than before the converter change. I believe the PCM is seeing what it reads as a trans slipping (because of the high converter stall) and it is changing the shift points. The bigger problem is it feels like the converter clutch is trying to lock in 3rd gear (off and on) even though it shouldn't be locking at WOT. I think Alan at dirty dog might have warned me the auto shifting may be a problem, I'm not sure. As a test, I'll remove the converter wire and try again later. If that corrects the concern in 3rd gear, the shift points might not be as much of the problem. I'm getting an overspeed code in memory (P1270 I think) which I thought I might get but I didn't think it would cause a shift/converter strategy change. Alan or anyone else see this before?, thanks.....Ken.