As you asked. I'm sure that we all wanna see the Cobra in the lead. I do agree with some of the other guys concerning the gearbox, a Auto box (and a shift light) will definitely give you a better chance in a straight line. Shelby's own 800hp Cobra was running a C4 automatic gearbox.
Here is a link to a Cobra Drag racing forum, lots of info there.
http://www.ffcars.com/forums/forumdisplay.php?f=36
Small things that ad up like running a full tank of fuel to put more traction on the rears, lifting the front end of the Cobra to displace the weight even more to the rear when launching, running a lower rear tire pressure and a harder front tire pressure. Weight savings will also help, get rid of all unneeded weight in the Cobra (spare seat and anything else that you don't need on the day, but keep the fuel tank full). Swap the full size windscreen for a small racing one, weight and aerodynamic improvement. Just keep it straight and on the "black stuff". Best of luck "Q"