There's usually a way to squish it in around the bolt there, so it's held in place. I wouldn't want to see it flopping around -- they tend to break pretty easily fi you're not careful.
I thought with the stock headers, the dipstick tube was on one of the studs? When I changed my headers, I didn't use any studs and put bolts in. I just held the tube in place(where it came off the stud), and tightened away. Stays there just fine.
I had issues with it and equal length headers before due to the wrap around tubing but I just used a steal hose clamp around one of the tubes and held it tight.. Kinda rigged but you had to look hard to notice it. unequals shouldn't be an issue.. might have to reuse the original stud.