105 springs are some of the easier on valve train springs that we have available. I would put them on w/o worries.
On the work invoved for a cam swap... I disagree, all the time of putting in a camshaft is getting the lifters out. If we didn't have to pull the lifters, it would take an hour or two for a cam swap at the most.
Lower cradle 20 min (including draining coolant and supporting car)
Pull timing cover 10 min
Remove chain and thrust plate 5 min
Slide cam out. 5 min
As for dropping a valve into the motor, if you have the intake off, you don't usually have to pull the head. The right sized magnet and a zip tie have been some of the worlds best tools on a bad day for me. Another trick is if you don't have air to hold the valves closed, ensure you've rotated the engine to have the piston up on the cylinder you are working on. Valve can't go far if the piston is at the top of the stroke.
