I don't think you are tightening it too much, but the silicone tube doesn't push too far onto the throttle body, so the hose clamp must be nearly flush at that end.
If your fist is smaller than mine, you might be able to stick your hand in one end, and make a fist to expand the end by the throttle body to get it to fit. I had to stick a screwdriver in the other end as a shoe horn to get it on; that and a bit of spit for lube. Once I got it on good (my third try), I ignored the instructions, and tightened down this clamp well; loosening it later for proper clearance on the aluminum tube.
That and getting out the radiator pass through were the only bothersome parts; the upper pin was a PITA. Took me over 1.5 hrs hrs, but I love the results.
I just finished my install a few hrs ago, and the SC sounds great !! Thanks Rob !!
Must be REALLY audible outside the cabin; tonight everyone wanted to race or play tag.