The code w/starting w/G refers to the gears in the 3rd members, the A340H is for the automatic tranny. As mentioned the auto will be a direct bolt it, and should work from any 2nd gen Runner/pickup.

If you can drive a 5-spd or ever wanted to learn, the swap is doable, you just need the cluster master and slave cylinders, the petal and linkage, and I believe a manual transfercase, I don't think the auto will still work w/a manual transmission. It will take longer and probably cost a bit more, but you will get better performance and mpg's for your effort.