Yes they are needed. Otherwise they will vibrate out. Don't buy the ones in that picture, they come from one fabricator and they suck. There is a reason why they are pictured from that angle and it does not show the 90 degree bend--they are cracked cause they are from the wrong material. I make the best reproduction and they are light years better. PM me if you want a set, mine are pictured on top, the bottom are several sets that I purchased like the one you pictured, they were all cracked. I sell the set for $27.50 shipped.