Hello @Takohtuesdays, have you seen LowRider V3 Calculator - V1 Engineering Documentation ? Can figure out required Strut size there (same size as Tube Length). Many of the common strut sizes can be found and downloaded from Jamie’s LR3 Strut Plate Variable on Printables.
I generated ALL the Strut plates using @jamiek’s OpenSCAD based script. Put the files here and here. Hopefully the LR3 Calc will be updated soon to include edits I made to let folks download LR3 Strut plate .svg directly.
Incase you/someone’s interested, I forked Jamie’s OpenSCAD script to create a LR3 Mod, tagged front grill with measurement markers, shared on Printables here. Cheers!