i have an 03 mach 1 and i bought the SLP long tube headers for it. ive already heard its a pain. im new to the mustang world ive been a camaro guy for awhile but i wanted to know i read somewhere that i should install a 160 thermostat with these headers to help lower combustion temps to keep from burning a valve. if i were to do this can i just install it or do i need a flash tuner when doin this will i need one for the header install also. im sorry ive been old school carb guy so im new at all this. i plan to get one of the tuners but i dont have one yet and i prob wont for a little while but i wanted to install the headers this weekend. i just wanted to know should i wait or what? im in SC so i have no emission restraints so i bought the kit without the cats. thanks for the help