The adjustable ones have the provision to be able to adjust their length with a nut and threaded screw. I may just use one to check the length and then order a set from TA
I looked. Only found 14. I know you can still get separate ones from Smith Brothers. $75 plus shipping. Let me know.
I had a set of 5/16" adjustables on my 430 way back when. Everytime I went past 5500 one would break. No joke. Once one broke and the lifter came out of its bore. I thank my lucky stars that didn't cause catastrophic failure.. anyways I'd be leary.