does anybody know what the difference in the dimensions on the front bumper between the generations and 2 dr and 4 dr models?
I bought a bumper for my 98 accord 4 dr and it doesnt fit and i cant return it trying to find out what year it's for

 

Unless you could possibly find someone from Honda with the original engineering drawings, I doubt you'll find a repository which holds this information. Nore do I think you'll find anyone here a....ly retentive enough to remember bumper cover dimensions.
I would suggest that during one of your kamakazi runs that you pay attention to other Hondas' around you so as to try to ID what you've got.
Either that, or post a picture of it here and maybe you'll luck out.