Do NOT use non-detergent oil to break in the engine. That's a myth that should have died years ago. Use a good 10W-30 of any brand and be done with it.
If the engine can't be started on the two valve springs now, then something is wrong. The inners don't add load anyways, they change the harmonics of the spring package. Leave them in.
Just add the oil and crank the engine for a bit with the spark plugs out. That will build oil pressure and fill the filter.
If you are fussy, go to a GM dealer and get their break-in oil supplement. Add that. It's OK to use - no other additives though.
Static timing is a bit of a trick. Get someone locally to show you.
Fire it up and don't allow it to idle for a good 30 minutes. Keep the engine at 1500 rpm or so, and rev it gently by hand. You'll be hovering nearby anyways, so diddle the throttle and stay happy.
Then drive it and see how it does. The rings won't seat until the engine sees a load - half throttle, half rpm. So what happens if you over rev a bit, or add too much throttle? Nothing.
I change the oil at 500 miles or so.
All the fussy business in the world is no substitute for proper machine work and assembly practices. If that's done right, no "break-in" is needed. If not, then all the special "tricks" will be for nought.
For what it is worth, all new Volvo engines, and those from all other manufacturers really, are run to full load, redline, before installation in the car.
Why worry?