I've read and agree with all the advice that you've received so far. I've often sailed a Catalina 27 which also has an 8 HP 2 stroke. You should be able to maintain 6 knots through the water under motor, but you'll be stemming a 1.5 knot current all the way so plan your trip at 4.5 knots which does make your 8 hours for 33 nm sound reasonable.
If you're looking for somebody to make the trip with you, I might be able to help you. I'm a retired Coast Guardsman with about 40 years of experience on the water, the last 6 years of which are on my own sailboat. With a new berth in San Pedro, I'm assuming that you live somewhere in the South Bay.
I live in Long Beach so it might be possible to work out some type of driving logistics that don't leave me in San Pedro with my car in Dana Point. If your new boat is short on electronics, I can bring my portable VHF and GPS as well as a jumper battery that I carry for emergencies. You can email me directly at email@example.com
Congratulations on you purchase and happy sailing,