I'm not sure about the difference on the v-8 and the inline 6 radiators ! I just sold an 89 260E and it had the 6 of course! but i never once had to get under the hood of it!
I did have it serviced regularly though! as for the part, That is it you have pictured! and it does have that number on the package 000 500 08 94 I purchased it from our Des Moines,Iowa Dealer
and they stuck me with a $9 bill! where did you find it that cheap? as for the 3 clips i said i had to break and not drop in the radiator are the ones on the bottom right side of you picture on the fitting. Then I had to keep the remainder the broken piece from falling in the radiator with my finger while My dad just ran a screw into the peice and got it out !