Part Number Question...

Can anyone tell me what the application or difference is for these rear bumper reinforcements. I know it would be for a 73 or 74 Roadrunner or Satellite but they all have different part numbers on them. Can anyone give me more information regarding the numbers on them?

1) Part #3686605 39239
2) Part #3754255 39329
3) Part #3754273 39329

Thanks guys!

From '73 parts book;

#3686605 - 2 door Satellite "up to 4-16-73".
#3754255 - same as above but "after 4-16-73".

From '74 parts book;

#3754273 - 2 door Satellite.

..... so, what's the difference?

bigger, heavier, more-better? got pics?

Thanks for the info. That's awesome!

I'll weigh them and take some pics tomorrow. I don't recall any differences but I'll certainly take a good hard look and report back.

I dug them back out today. The 74 has the bolt holes in a different location. I assume it's relative to bumper guard style. I should of caught that sooner. Still not sure what the difference is between the two 73 pieces though. I'll have to do a little more homework on those two. Anyhow, here's a pic of the three of them together. -Trent