WOT Passing gear issues

[Meatwad]

Hello all,

I have a 1991 Caprice Wagon and I have an issue passing at WOT. First let me give you the car's specs (its stock).

1991 Caprice Wagon
L03 305 TBI V8
700R4 Transmission
3.23 posi rear end
121K on the odometer

When I'm going about 60mph and up and I need to pass the car has issues. If I push the pedal 3/4 down, it will downshift and accelerate smoothly with lower engine RPMs (don't know how much, I dont have a tach), but if i go WOT I get no acceleration, the engine winds up to high RPMs. It is as if I put the car in neutral first. Is this typical behavior with this engine? If not then what's wrong with it? The trans shifts are smooth and crisp, unless its really cold out and the engine hasn't warmed up.

Also I have a PROM from a 1992 9C1 for a L05 (350ci TBI). I tried installing it, but the car ran horribly when I did. Any reccomendations on how to, if its even possible, make this work with my car and if using it will help performance.