About 35 years ago, I stopped in Ron Roland's shop, and I had a transaxle mount bolt missing, so he replaced it. Now that I am going over engine/transaxle cleaning, powder coating, chroming, etc., I am wondering if the 4" or 4.5" bolt is the correct one (see attached images). Based on the grime/grease patterns in the threads, the shorter bolt looks like only about 3/8" of the threads were used, while the longer bolt appears like all the threads were used.
I am replacing these with new zinc-coated variants, and want the same appropriate bolt length.
Below is the 4" inch bolt:
Below is the 4.5" bolt:
