rethreading thermostat holes from 5/16 to 3/8 ?

Thank you.

I stand by my previous advice.

Why drill the hole larger, then buy and install a coil, when you can simply drill a smaller hole and use the next size bolt?

The only thing I can think of that would preclude this is if there weren't enough clearance to get a wrench/socket on the head of the larger bolt.

But since we know Mopar went to 3/8 bolts later on, it's likely not an issue unless they redesigned the housing, making the bulb for the hose smaller.