Should I worry?

[ZCurves]

From reading your post, I do not think that running a block or two will kill ya. It does not take much at all to peg the temp out. You would have immediately noticed hard starts, rod knock, and/or steam at the exhaust from a warped head or blown gasket. I would suggest that you change your oil at the very least and look (listen) for any of the previously mentioned symptoms of damage. Your oil certainly was 'Stretched' by running at that temp - besides a change is cheap (considering).