What VFR cruising altitude should be flown to the west below 4500 feet? This is similar question to this question, but different scenario. 

Let me describe the situation:

I am at KDYL in class G airspace. Accroding to ATIS the clouds are at 4700 scattered. I am going to fly west. I would like to fly below clouds. I will need to have 500 feet clearance below clouds in class E, so it is going to be 4200. 

Do I have to comply 91.159? What altitude should I fly? Can I fly 3500 west in my scenario or I have to descend below 3000 and fly any comfortable and safe altitude?
Yes, you would have to comply with §§91.159.  If you’re flying VFR westbound (180°-359° magnetic) at >3000 ft AGL,  you will need to fly at even thousands + 500 ft, except while in a holding pattern or turning.  For a forecast of scattered clouds, you will simply deviate from your course for cloud avoidance, then return to the route.