F-22 has 84000 lbs of MTOW and powered by 35000 lbs engines.
If TFX will have 70000 lbs MTOW, and then 29000 lbs will be enough
If TFX will have 77000 lbs MTOW, and then 32000 lbs will be enough
So the existing F-16 engines enough for a start up. This gives you time to develop an indigenous one(s).