Good place to buy Frame-connectors?

Mopar performance makes them for the a-bodys.

Not sure if your car's wheelbase is 108" or 111" but here are the part #'s.

108" wheelbase p4286868
111" wheelbase p4876658

Summit has the 111" for $141.00 plus a 8 or 9 dollar handleing charge.I like Summit alot.Plus you have a true Mopar part.

Do a search on the net with the part #'s.

Hope this helps.
John