If the 01 = Mach 1, then I wouldn't go over 400-450rwhp. The mach 1 engine does not have forged internals, the most you want to push on them is 400-450 to be safe. you MAY be safe going a bit over 450, but I wouldn't risk it if you want the engine to hold.
The 01 cobra and mach 1 blocks are aluminum with no forged internals, the termi has an iron block with forged internals and ARP bolts. So, the mach 1 motors have pretty much the same durability as most other mod motors, 400-450 to the wheels
conclusion: don't go over 450rwhp on an 01 cobra/mach 1 motor, unless you plan on forging the internals.