I agree, I have had good luck with POR-15- if the surface is properly prepared. I have also had good luck with Hammerite (made in England and hard to get), which takes less preparation and rolls on nicely, and does not require an overcoat of UV-resistant paint.

One area often overlooked on 1st-gen 4Runners: the inside of the rear wheel wells. What happens is, as the interior heats up, the moisture condenses on the inside of the cold metal body, then dribbles down to the base weld of the wheel well where it starts to rust. You can pour some sort of solvent to remove splooge from there, let it dry, then pour a good paint in. Warning, you will find all the pinholes and dribble all over your garage.