I've got a set of V&H long shots and the previous owner said to use the smaller SE gaskets, but the guy at the indie said regular gaskets are good to go, so that's what I bought, but haven't installed them yet. Does it really matter?

 

I don't know if it matters or not I do know I could not get my bassanis to seal with oem gaskets went with the se gaskets and no problems so far, as for the long shots v&h recommends se gaskets

Check condition of stock exhaust gaskets. Replace if worn. Vance & Hines recommends you

replace your gaskets with Screamin’ Eagle gaskets, part number 17048-98.

http://www.vanceandhines.com/download/D270IN.pdf