Sunoco LP (NYSE: SUN) could be a solid addition to your portfolio given a notable revision in the company's earnings estimates. While the stock has been gaining lately, the trend might continue since its earnings outlook is still improving. The upward trend in estimate revisions for this master limited partnership reflects growing optimism of analysts on its earnings prospects, which should get reflected in its stock price. After all, empirical research shows a strong correlation between trends in earnings estimate revisions and near-term stock price movements. Our stock rating tool -- the Zacks Rank -- has this insight at its core. The five-grade Zacks Rank system, which ranges from a Zacks Rank #1 (Strong Buy) to a Zacks Rank #5 (Strong Sell), has an impressive ...