'89 xj overheat, temp gauge pegged...what should I look out for?

Catastrophic lower radiator hose failure on '89 w/ auto. In a blocks distance lost all my coolant through 1/2 inch slit in hose. By the time I pulled over and killed motor, temp gauge had just pegged. What should I be checking to see if I did any damage? Need to get more coolant, but noticed on restart that engine doesn't idle up as high when in neutral or park, used to be 800-900 rpm, now 600, same as when it's in gear. There's no engine surge or drop when shifting between drive and non drive gears. Any ideas.

Head gasket is what to look for. Check your oil (if it's time to change it go for it), if it looks wrong (bubbles, looks like choclate milk) than the gasket it bad.

Depending on how long it was peged you could be fine. I was forced once to drive it for about four or five minutes on a totally peged guage (couldn't get off the freeway and there was no shoulder) with no negative effects.

The 4.0 is a solid engine!

Sequoia

Oh, might be a good time for a cooling system R&R if it's all original. Personally I'd go for converting the system to a newer "Open" sytle, that's what I did with my '89.