i have some ? about my e30? its differt to all of my other ones

[boogs325ic]

i have a 1991 bmw 325 it doeset say i or e on the title and rreves out at 5100 and has the supper eta head stampes 2,5 and 2,7 on it can someone help me out its a base modle to no popouts no 13 botton... ill post up some picss as soon as i can..:ohsnap::loco: