Allin.

When both of you have such short stacks like this heads up you need to be the agressor.

I hadn't played with my friends in a long time, then just recently did this past weekend. We all had stacks around 4,500-5,000 with blinds at 300/600. They kept saying I sucked by moving allin preflop instead of raising it to 1200 or something. I just smirked and kept up with it. Once it got to heads up both of our Ms were lower than 7, and I went AI pretty much any 2.. My friend said I had become a terrible poker player and ended up calling without looking because I "sucked."

But back on track, if you fold or just call with K8 here it is a bad idea. You need to either raise and make him fold, or raise and have it be basically a coin flip (unless you're unlucky, which you were).