lol, good attitude
Now that I see what you have over your tank, I can see why you don't seem to be too concerned. The 2X4's would handle the weight ok without collapsing. I still think your access will be close to zero, which will be a big PITA in the future.
One thing you have to consider...glass has marginal compressive strength. With the 90g empty, yeah, it would "probably" be OK. But once filled, your tank IS bowing. It may be minimal, but the water is going to bow your tank somewhat. Now you put 160 lbs on top of bowed glass. You have large forces pushing both down and outward.
Hold a saltine cracker vertical with your thumb on the bottom edge and your index finger on top. Then squeeze. Basically, this is what very well could happen to your tank walls.