Head flow and RPM will be your friend hear to make the 431 work. A good set of aftermarket standard size port heads, single plane intake, 1 7/8 headers and a matched solid cam to run 6500 to 6700 rpm will help you build power needed to make your goal. If it is not too late, relieve the cylinders at the top of the bore next to the intake valves like the 426 SS motors did to help intake flow. Be carefull not to go to far down the bore.
On the size of the cam, it will take duration in the 255 + range at .050 cam lift with total lift of .550 or more to make use of good heads and reach your goal. The highest gear ratio you can tolerate out back will help as well. A 4.10 gear or more will help a lot but if you can tolerate a 4.56 I would go with it. Combined with a 27 inch drag radial for the track and the tallest tire you can stuff under it for the street, it should work pretty good.