The smog stuff on California Olds models didn't really account for much hp loss. Maybe 5 hp tops. Removing the smog pump won't get you anything except a little weight loss. Removing the EGR won't get you anything but the need to completely retune the fuel and spark curves. As it is you're running an engine on 93 octane that used to have 100+ octane leaded gas back in its day, so removing the EGR will not only give you next to zero HP, it might make that 425 ping like a bell. That 425 is using very dated chamber designs in an iron head with 10.5:1 compression. By today's standards you should be running nothing less than 100 octane in that thing. That smog stuff is the main reason you can get by on cheaper fuel today. It was rated at 385 gross hp, so its probably actually only putting about 280 sae hp to the wheels.
Smog stuff isn't responsible for any real power loss in 1967 Olds stuff. You are dealing with a 4400-lb car, ancient head designs, and an engine that was rated by gross HP, so what was fast back then isn't really fast today. You probably already knew that, but don't blame the smog stuff. Blame the old cam, heads, and intake
The good news is that there are later Olds heads, cams, and other parts that will really wake that 425 up while dropping the compression. Later heads offer much more efficient chambers, better flow, and overall you can pick up a lot of HP with a compression that will help out at the pump.
The REALLY good news is... what a sweet car! I love those Toronados. Lucky bastard.