t.b.i. problems

[tellezj]

i've been having problems with my small block on my truck.when you floor the gas pedal it starts to go very slow it does not get the passing gear and when its at high rpm the truck starts to studder it starts cutting of like it needs more fuel or spark its really slow. I've replace the transmission, fuel pump and filter, did a t.b.i. rebuilt, distributer rebuilt, new plugs and wires, new coil replace air filter. i dont know what to do with the system im planning in making it a carburetor but thats one of the reasons i fix up this truck because of the t.b.i. no mecanice where i live has found anything wronge with it o and also replaced the computer with a brand new one please help me with the problem i have.
its a 1987 chevy 350 with a tbi and a 700r4 and sometimes it feels like if the clutches on the trans are slipping you floor it and it just revs up