Introductions discussion

Hello Can you give me some guidance? I’m looking to increase the gap on my Jailbird. The total length from the bottom of my pelvis to the tip is around 60 mm. This measurement shouldn’t exceed 60 mm, though. My flaccid penis measures 2 inches and the current opening in my device is 3/8 inch. I’d like to switch to a 11/16” gap. I feel this might make the cage too long, so should I reduce the overall length by widening the gap and choosing one size smaller for the cage body? The 60 mm total works well for me; my only issue is with the gap width.