Sounds like a good plan but I think the 39 is closed...see below from the Angeles Forest website:
Current Road Closures
The Angeles Crest Highway (SR2) is closed between Islip Saddle and Vincent Gap (indefinitely because of several washouts). (State)
Ridge Route from Lake Hughes Road to Templin Highway - All modes of transportation (Forest Service)
Glendora Mountain Road - Closed from the City of Glendora north to the Glendora Ridge Road (County)
Highway 39 - Closed from just above the west fork of San Gabriel Canyon (State)
The Santa Clara Divide Road between Mill Creek Station and a point one mile west of Alder Saddle is open (there is a total washout 1/4 mile west of Alder Saddle); this includes access to Mt. Pacifico Campground. (Forest Service)
The gate to Skyline Park Picnic Area and the observatories is open from April 1 through November 30, 10:00am to 4:00 pm.