5100s and FJ springs are a good plan. I ran a Daystar 2.5" spacer and FJ springs in the front of my 4R for about two weeks. It was too much front lift (3.25") so I swapped out the spacers for 5100s (at the 1.75") setting and FJ springs to get 2.75" front lift. The rear runs DS 1.5" spacers and FJ springs for about 2" overall lift. My kid liked it better with the taller front end as the truck had no rake but since I load it up for camping from time to time I prefer a bit of rake so that it levels out under load.