More details please? Are these both new 2014 models? Used 2005 models?
Ram 5.7L/8-spd would be best powerwise.G M 6-spd with 3.42 is not as far off Ram's 5/6-spd for net wheel torque, but way less than the Ram 8-spd. However, the payloads are the lowest in class so you might only have 400 pounds left for people and cargo in the bed. 2014 GM has the highest typically equipped on dealer lots payload with about 600 pounds more than typical Ram.
So besides which truck you like to sit in, drive, pay for, you need to balance payload vs. power. A 2009+ GM 6-spd/3.42 will be better than your Ram 4.7L. A 2014 GM will be even more so. And the Hemi 8-spd the most powerful.