I bought a 96 ss back in febuary for $3500 the transmission needed rebuilt (I have a great donor car) i had the tranny put in and it ran fine for 2 or 3 weeks then the opti went out i had it replaced (ac delco) along with a water pump a crankshaft position sensor reluctor ring timing cover new plugs and wires had to change the pcm cause the former owner took the knock sensor out so i replaced it with the 97 pcm changed the wiring harness to the 97 which the former owner had put an OBDI harness in and still had the OBDII pcm this car was highly AFRO SHEENED. The only codes that the car is throwing now are for a O2 sensor right bank and the sensor for the cat converter(removed) i have an O2 sensor to replace the one in the manifold and am waiting on a simulator for the cat. NOW TO THE POINT at WOT around 4 1/2 to 5 grand the car starts cutting out like a rev limiter but has started to do the same as low as 3500 so i dont believe that is the problem occationally it throws a egr valve code but not often i clear it and about a month or two later it'll come back. Could an O2 sensor or EGR valve make it feel like its just losing all power. if i stomp it at around 35 the rpms slowly rise and everyting is fine but when i stomp it around 27-28 and it drops a gear the rpms shoot up and thats when it starts to cut out.