good luck fitting headers into your car! i really hope it does not have AC.
put the car on jackstands, as high as you can. use a cherry picker and lift the engine about 16", you may need to lift more.
after you bleed, sweat and cuss, ALOT while getting the headers into position. ( beer & medicinal herbs helps this greatly if its your thing)
remember 1 thing.on the siameased exhaust port, the rear bolt must be put in before you slide the header into place.
now that your cussing again, please remind yourself that theres a gasket that goes there as well....BEFORE YOU PUT THE REST OF THE BOLTS IN..
hint. remove oil filter adapter, starter, trans lines, and in some cases shifter linkage. and use 3/8 head header bolts.(gives you more room)
i find it easier to tighten all the bolts while the car is still in the air from the bottom, besides the center rear bolt, i have a 3/8 wrench i cut down to fit this tight place.