I have purchased shocks for '60-'66 Chevy trucks from
www.lmctruck.com, www.chevyduty.com and
www.bowtiebits.com. There are other aftermarket truck suppliers that carry correct replacement shocks. I have a factory '66 K10 that needed new shocks. I had them replaced at the tire store while they were redoing the brakes and mounting new tires.
The aftermarket truck suppliers tend to be a bit higher on some of the consumable parts like shocks, etc. however you are saved a lot of frustration during installation, because they know what you mean when you say shock for a '61 Chevy K10. Good luck and hopefully this information is helpful.
