Not sure from your reply if you will drive through Vrsič pass to see close up the Julian Alps, or go directly to Adriatic via easy highway route. In 2017, we drove the Vrsič pass route but only to village Trenta (we had terrific lunch at Gostilna Motoja) and then turned back to Bled. We made number of pit stop for sight seeing, and the round trip took six hours. As was mentioned previously there are some 50 turns in each direction, so be ready to use that clutch. For us, the drive was well worth it.
But I wanted to propose two alternate ways to see Julian Alps/Triglav National Park.
First, drive to Bohinjsko Jezero and take the tram to Vogel Ski center. That will give you nice views of the lake/valley and into the Julian Alps. After the tram ride, you can also take the ski lift up to the mid-peak, or choose to hike like we did (45 minutes at leisurely pace), for even better view toward Triglav, and can also have lunch at the mid-peak cafeteria.
Second, drive to Mojstrana and take local road 908 to Aljažev Dom. At end of that road, park the car and walk 1/3 mile to the mountaineering home (all flat), and from that location you will have a perfect view of Triglav that towers above you. We stoped there late in the afternoon, and had palačinke (crepes)....delicious.
Enjoy your trip.