So, I recently replaced the thermostat in my '93 5.8L (which fixed my overheating problem.) but was surprised to find that the old one had been installed backwards.

The previous owner was a mechanic, and it seems like a really stupid mistake for him to have made so I am wondering if there is some reason why this would be done intentionally.
Is there any benefit, or was it just a stupid mistake.
Also, could this have done any damage?

Thanks!

 

Maybe he had too many beers

 

Only cause it to overheat like it did. With it in backwards the hot coolant in the block just doesn't hit the temp sensitive portion of it and it takes it forever to open hence causing the overheating problem.