87 Mustang overheated, now runs rough

[badgurl]

I just bought a 87 Mustang 2.3L hatchback for $200. The friend I bought it from said the electric fan went out and the temperature gauge went sky high. At the time he was sitting in traffic on a bridge on a hot day and didn't stop.
the hotter it got the rougher it ran. as he made through traffic and back up to speed he drove a few more miles to home. It ran real rough.

After I took the head off the gasket showed no signs of distress or leaking between cylinders. however there were some plugged water jackets in the head.

If the gasket wasn't blown, what else could it be? the head is a cast head.

[angus10]

It might be cracked,or the block is cracked, how's the oil look? Only way to know as far as the head goes is to have it magna fluxed.

[badgurl]

The oil looks fine, no water or murky looking. I have an opportunity to get a used and tested head for $150 and thought that maybe I should do that instead of wasting time on the magniflex process since I have it all apart.
Thanks for your response

[angus10]

Worth a try I guess for 150, hope that's it, good luck. And please keep updating, most people don't. Hopefully you are lucky enough to not have any cylinder, bearing or piston related damage. Clean up the block mating surface real good and see if you can see any hair line cracks too.The oil looking ok is a plus. Check the coolant too.

Good luck, hope it works out.