stock floor board seams? you need to raise the tranny tunnel too, otherwise taking the trans out later on will be hard.
take the dash out, take a picture of the firewall and I will MS paint a cut line for you. Or check out seth's (twistedminis) bodydrop how to here on ssm, he's not hard to find, 9 of 10 threads are about him, his truck, or his control arms. seriously though, there is a good writeup with pictures, its a toyota but the same exact principles.