I've used the Crane variation and it didn't seem to make a whole lot of difference. Added a bit more vacuum, but I doubt it would cure your problem. What type of carb are you running? I've gotten some engines to pass in the past with pretty decent cams (low duration high lift) just by adjusting the carb and accidentally forgetting to hook up a few vacuum lines. The vehicle ran pretty bad, but it passed the sniff test.
Here's a few other things that might help also. Use these plugs, available at most Advanced Auto Parts stores. They aren't cheap though.
http://www.e3sparkplugs.com/
Run the tank low on gas and dump in a bunch of dry gas. If you have oxygenated fuel in your area, use that also. Make sure you have a 195 thermostat and the engine is warm and up to operating temperature.
I'm not sure if you can do all these because of compression ratio etc. You might be better off taking it to a local garage where they can mess with it for a bit to make it pass. I was lucky. My brother worked at a place they had a 4 gas analyzer, so we had lots of time to make the vehicle pass.
Good luck.