Summary - This traverse starts from the Silver Star trailhead (45.78080, -122.24362) and links Silver Star Mountain with 3977 (Discriminator). Covering roughly 8.5 miles and 2800 ft of elevation gain, it has amazing views, some steep sections, and a bit of scrambling. Do 3977 first to get the toughest part of the hike behind you, enjoy the big views on Silverstar and have a mostly downhill walk back to the trailhead. From SE Portland to the trailhead is about ninety minutes. Caution advised when planning the drive: FR41 is not Prius-friendly. ATT cell service was good, as was APRS. A Discover Pass is required for parking.
TL;DR - There are several ways to get to the trailhead. To avoid as many of the bonejarring ruts and potholes of FR41 as possible, picking up L-1100 from NE Sunset Falls Road, which connects to FR41 less than 2 miles from the trailhead, is a good option.
Silver Star and 3977 are less than a mile from one another as the crow flies. The hike between them is closer to two miles and drops into a saddle close to one thousand feet lower, making this a hike with a lot of up and down. Starting at the Silver Star trailhead, you can follow Silver Star trail (180) or Ed's Trail (180A). The two trails run on opposite sides of the ridge, and I recommend you go up on Ed's. If you want to save some time, return on Silver Star. Ed's is the eastmost of the two, on a trail rather than a old road bed, with beautiful views of the steep valley and surrounding mountains. It does have a short section of class 3 scrambling and a bit of exposure where the trail crosses very steep terrain; good shoes and trekking poles are recommended.
You will follow 180A for about 2.8 miles to the junction with trail 172 (bloom mountain). Head east on 172 for roughly a mile and the junction with trail 175 (starway), which goes north and drops steeply. Starway takes you to the summit of 3977. Be prepared, there are sections of steep climbing in both directions. 3977 is an open summit, bring a mast if you want to use a wire. ATT cell service and APRS both work well here. When you are done, retrace your steps. At (45.74858, -122.23973) you will find a trail going up and to the west. Follow this to the Silver Star summit trail and keep going up until you can't.
Silverstar, like 3977, is generally treeless and you'll need a mast if you want to put up a wire. It is also very, very popular when the weather is nice. When you've finished, head down the hill, turn north onto the old road bed, which is Silver Star trail. You can follow it or pick up Ed's trail again to return to your car.
The traverse between Silver Star and 3977 is short but mighty, with lots of up and down and up and down, and the loop hike combines ridges, alpine meadows, forest, great views, and a bit of scrambling, all from a single parking lot. The trails are all in good condition and the only downside to the outing might be the crowds on Silver Star.