I have a custom built comp with sempron 3100 + I have overclocked to 2.2ghz no probs there everything seems fine cpu chip is avg 31 c 40c with load but my chipset is at 77-78c
Ithink this is too hot not sure. if so how can I lower it are aftermarket heatsinks worth it, or am I just paronoid.

I think that is extremely hot for the board. Your CPU is just fine.

I would definitely add a fan which will depend on your board. Here is a Google idea:

http://www.google.com/search?sourcei...hipset+coolers

I am currently installing my first water cooling system which has blocks for both the CPU and the Chipset. I'm mainly doing it for my CPU as it runs 50c idle to 75c full load.

My board had a built-in heat sink over the chipset which runs @ 35c to 39c.

Hope this helps.