1998 3.0L 4x4 Manual Ford Ranger towing 1500lbs with tow package?

I'm not too worried about it on the freeway, how will it do on moderate uphill road? I want to buy a boat and take it up to the lake. The boat I'm looking at weighs about 900 lbs, so I'm making a liberal estimate with trailer, gear, and gas.

No problem. Don't even need a towing package for such small load. Most mid size cars are rated to tow 1,000-1,200 lbs or so, so 1,500 for a Ranger is well within it's capability. Just be mindful that you may take longer to accelerate to speed, as well as longer stopping distances from speed. And if you find yourself climbing a lot of long hills, keep an eye on your engine/trans temp unless it's equipped with additional intercoolers.

You can tow 1000 lbs with a ford focus 2L - no worries with the truck.

My little factory bumper on my 99 dakota says max weight, 2,000 lbs.