Overclocking an NVidia Vanta

I have a 16MB 2X AGP NVIDIA VANTA graphics card whose stock speeds are 100/125. I have used Riva Tuner to overclock going in increments of about 5 with the core and mem and thourghly testing it with about 5 or 6 loops of the 3DMARK2001SE Demo and so far I've been able to get it to 140/167, anything higher than that and I start to get artifacts or it locks up. Now I know that most of the time its the memory thats the bottleneck in a system so my question is. Is it really worth it to keep the corespeed at 140 or should I turn it back to like 130? The reason I'm asking is because both the core and mem are outside of the blue bar thingie and whenever I touch the HS on my GPU it's almost hot enough to burn me to the touch...thanks for all replies.

~jeff~

You may want to try aiming a fan at the chip or using more cooling. Try reducing speeds until performance starts to suffer, when the speeds are the bottleneck.