Changing the tranny fluid

I'm going to be changing out the tranny fluid this weekend. There are 196,218mi on the jeep and I know nothing about the age of the fluid. I have read several posts and would like some input. I was going to put 10w-30 in it but trying to determine Syn or Conv. Is there a pro/con of each? Is the Syn better than Conv and why?





1997 Wrangler

2.5L

5 speed manual





Thanks for your time