'96 bird speed limiter issue
 

Hey fellow gearheads! Hope you can help me with this one.
I have a '96 4.6L bird. Shortly after purchasing the car used I decided to gear down the rear end from the stock 3.27's to some 3.73's. Before I geared it down, I went out on some flat highway to see where she governed out at which turned out to be right around 160 km/hr. After putting in the 3.73's the top speed dropped to a little under 140/km hr. I had also purchased a hypertech programmer so hooked that up and discovered it would only allow me to increase speed limiter to some rating (which i cant remember) of performance tire. There is only one option to increase top speed limit from stock. I am running larger aftermarket rims with low pro Falken tires that have a higher speed rating. With the hypertech programmer higher speed governor setting I'm back to a top speed of just under 160km/hr. Of course this is sufficient, and rarely do I drive that fast. But, every once and a while on some clear, flat, wide open road a guy might just want to let the ol' bird spread her wings and fly! I know there's lot's left in the engine, it's just that damn computerized **** holding 'er back.

How can I get around this?

Thanks for any info! Dusty