Replacing the cross member and associated parts is more work but then EVERYTHING is one year model. You can do it a bit at a time from junk yard donors, but this isn't my favorite approach. Either swap the cross member or Everything off one truck. either way, you'll have to replace worn parts. This is a great time to go to power brakes and power steering, too. If you can find a pair of 71-72 axles they'll give you 5 lugs all the way around.
best wishes,
Les
