Ben

Hi guys- im new to the forum (and new to an old dt 175.) at least, ive been told its a DT175, but i cant find anything that tells me for sure, also, I need to know the year of the bike. I dont have a photo right now, but it has a monoshock, appears to be late 70's, maybe early 80's. Can anybody tell me what some distinguishing factors might be of the years? Thanks Ben