Are they the same as the post 98 lower's? i know the older one's are return style but can i use an older one on my '00 model?

You would NOT want to downgrade to the smaller LIM of a non-returnless.

However yes it would work to use a return style 96-99 LIM.

Thanks again Demon. the reason i wanted to know is because i have a pre 98 lower that i am going to machine out and put larger butterflies in for the secondaries. i just wasn't certain. when i had my lower off for the cleaning i didn't pull the injectors. and when i pulled the feul rail off the older one, the mounting bosses for the return style injectors just looke dlike it might be a little different from the newer manifold. again, thanks for your help Demon