my pressure sender is mounted where the oil switch was mounted at the back of the block on the main oil gallary. Just to make sure i took the oil pressure gauge kit out and mounted in my friend's evo at the exact location and he was getting 80 at start up.... i am begining to think the build might have a problem now

 

you've ruled out everything i can think of. i dont mean to insult ur intelligence but have u checked ur oil level recently? where did u ground the sender?