Hi, I'm new to the cobra's and I keep reading that some of the sfc's "require modification" for use on cobras. Is this true for all or just full length? I see mac makes a set of cobra specific ones part number mac-sf9600, but there's no pic to see what is "specific" about it. any info would be appreciated. I'm looking for them for my 97, it's mostly stock, just flows, gears, an drag radials. I'm worried about runnin the dr's at the track with out the sfcs. thanks.