Ah, that makes sense. You have 32mm tires (32-630) which are really 1-1/8" (despite the label saying 1-1/4"). 90psi is not uncommon at that width. Still fine for rough roads. Your tubes should be fine too. 27" wheels are rare these days, but I wouldn't replace them with 700c wheels on this bike unless they're in bad shape. If you do, you'll have to move your brake pads down about 4mm, so you might want to check that your brakes have enough room for that.