For the power curve, the best place to start is probably googling something like "289 xxxHP dyno" (where "xxx" is your target power) to find yourself a real-world, representative power curve. Odds are you'll find something pretty close. I usually do.
For putting it into AC, this is a useful tool:
https://acstuff.ru/u/torque-helper/
Bear in mind that the numbers in power.lut are
torque, at the wheels, in nm - so you may have to do metric/imperial conversions which are easy at sites like this:
https://www.convertunits.com/from/lb-ft/to/N-m
As the dyno chart you'll find will probably be taken from a chassis dyno, the numbers will already be at the wheels and you may not have to factor in driveline losses. If you do that's easy enough using the tool linked above.