Something I don't get here. Minimax 1600R, Drawing 21. Bolts securing the upper rear strut outboard straps is AN3-14A but the bolt that goes through the upper block (block-strut) is an AN4-15A. I can't see why the extra length is there, it looks as though the right bolt is AN3-14A. The horizontal bolt is an AN4-17A which checks out.
Is this to allow movement?
Is there anybody out there who can confirm this please or alternately, deny it and explain what I don't understand.
Thank you.

On my strut connections (at both ends of both struts ), I have noticed the plans call for bolt lengths that are a tad too long. I have eventually replaced many bolts on the struts with sizes that fit ( usually one length-size smaller ) . Not sure if my Max is an outlier or this is a common occurrence.

Yes, that makes sense.I am having to convert quite a lot of sizes because I am fitting streamlined struts. I shall look at the fittings as I bolt it all up.

An AN3-14 bolt has a grip length of 1.13 inches while an AN4-14 bolt has a grip length of 1.06 inches (not enough!). While the total bolt length including the threaded portion is the same for the same dash number, the larger diameter bolt has a greater threaded length and therefore a shorter grip length.  I didn't know this.  The AN4-15 bolt is an eighth inch longer than the AN3-14 bolt but the grip length is only 1/16" longer.

Ah! Thank you Bob. That explains it. There is movement in the joint but not 1/8".