Does this look like '72 suspension?

[NorCalC20LWB]

Posted this on the general 67-72 board, but did not get any opinions. Anyway, pulled my engine for a rebuild and started pressure washing the engine bay/suspension for a clean up & paint. The suspension, specifically the A arms sure don't look 44 years old to me, upper ball joints are still riveted in, so would think original. The rear end in the truck is from the mid to late eighties, so I'm wondering if the front has been replace also?? It's a C20, drivers side upper A arms have 3785 stamped on top, passenger side 3786.

Thanks for any input...
Brian