The last two I bought on eBay and were made by Lucas. One was $4 and one was $6 with free shipping. The NAPA one should be as good as any. Keep the old one in your glovebox for a spare. BTW I'll be motoring to Chippewa Falls, WI in two weeks enroute to the Canadian Rockies.
Just looked at the OE one on it and it's a Motorad, Mexican made. So is the Napa one...so I presume it should work. I think Motorad makes Tstats for Jeep as well.
Sounds like a fun trip! I'm about 1.5 hours due south of Chippewa Falls. Going to get some Leininkugels?
I've never had an aftermarket cap actually fail, but I always notice cracks forming in the gasket after maybe a year. OE caps don't seem to have that issue so soon.
Even though Motorad is the supplier, the NAPA cap may or may not be the same as the OE one. No harm in trying it though.
Almost any OEM-quality cap is fine. They have to hold a very specific pressure range so there is no room for variation.
You can look at aftermarket race-oriented caps which will hold higher pressure, but your entire cooling system has to be able to hold that pressure. Not really needed in a non-track car.