The owners manual for my 2010 Silverado says the bulb number for the front turn signal/parking lights is 3047. However, this site, http://www.sylvania.com/ConsumerProd...de/default.htm , shows the number as 4157NA. When I do a search for the bulb number 3047, most of the results show up as 3157. Are these bulbs interchangeable?

Thanks