Is Carquest Dex/Merc ATF Fluid ok? It says Approved for H Specification and should be used when Dexron, Dexron II, IIE, IIIG or IIIH are required. Is there a better fluid I should try and get?

I am going to do another change in about three weeks, to get some more of the fluid changed out, as I don't know if it has ever been done. When I do that, is it critical I use this same exact fluid?

 

That is the wrong fluid, the book says Dexron III, not III(X)
So I would have to say no, and if you already put that in then when you change it put the right stuff in and you should be fine.

 

Spike,
About a year ago when having my head gaskets replaced and talking with my favorite Rover shop owner, I saw some of Vavoline's Max Life on his shelf. We talked about it in depth and he has been using it for about a year because of it's additional benefits to trannies over 75,000 miles, mainly leaks, slippage,shudder and metal wear.
This product may not be listed in our owners manuals, since it is relatively new, but works well in or ZF trannies.
Pretty neat product for only about 50 cents more a quart.