OC settings advice from the experts

I'm new here. So first let me say hello and thanks in advance to all who
spare a moment to provide their thoughts.

I have an ABIT IS7 motherboard with a P4 3GHz/1MB over clocked and stable
at 267Mhz. So my 3GHz CPU is running at 4.005GHz. I'm using the stock
heat sink and fan on the CPU. I'm running Windows XP Home Edition. I have
the following settings and temperatures at idle and at load while running
Prime95 v2.38 at maximum torture settings:

Bus setting: 267/76/38
Memory: 5:4 (512x2 DDR PC3200) someday I'll get PC4000 and try 1:1
AGP Setting: 7:2:1
VCo 1.6v (Prime95 produces errors at voltages below 1.56v)
DDRcc: 2.70v
+3.3: 3.3v

Temperature at idle:

Sys: 34c | CPU: 54.5 +/- 5c | PWM: 50.0 +/- 5c

Temperature at load (Prime95 maximum torture setting):

Sys: 37c | CPU: 75.5 +/- 5c | PWM: 75.0 +/- 5c

The system is rock solid at these settings and Prime95 ran error free for
two hours. No crashes. No I/O problems with Sondra2005 disk drive test.

Are these settings and temperatures safe? Am I walking on thin ice, or
living on borrowed time? Any suggestion, comments, observations? Any
suggestions on a better heatsink fan combo that will fit on this MB
inside by Antec SLK1600 case (300watt stock power supply was upgraded to
450watts, hey what can I say, the case was free).

Thanks, -Barry