Luke, I agree with the above recommendations. I also rescue mowers & outdoor power equipment from alleys, trash bins, etc., and combine the good parts to make working mowers for family, friends, and such. It's fun. But, there are parts compatibility concerns between makers. Some of the main manufacturers, like AYP/HOP, MTD, Toro, Honda, and others, might use a similar engine with a 25mm (or 7/8") x 3-5/32" shaft, they don't all use the same dimension blade adapters. Take a Toro 22", pull off the engine, blade adapter and Atomic blade, and stick it all on an AYP/HOP or MTD 22" deck. The blade tips will extend BELOW the lower deck lip. VERY dangerous. Toro (and Honda) have a greater engine mount to lower deck lip distance, and the blade adapters (and blades) make up for that. So, in reverse, take an MTD-made Craftsman 22" (or an AYP/HOP-made Craftsman), put the whole engine, adapter and blade setup on a Toro. The blade tips will be further up into the deck than it's designed for, making for poor performance. You have to have the right spec'd engine, adapter and blade for your application.
And just as the Honda Tech stated, the engine you have is NOT designed for mower applications WITHOUT a Roto-Stop or BBC (blade brake control) system. The heavy flywheel is meant to provide the rotational weight the blades usually provide, and it lacks a grab-bar activated ignition cutoff as well, which is activated by the flywheel brake control when the proximity grab bar is released. And I'm sure you were already familiar with this info. One of my extra mowers is a GCV160 with a BBC system (heavy flywheel). IF the BBC system froze or broke, I'll probably take one of my junked GCV160s and see if the lightweight flywheel and control components fit onto it (including cable and proximity bar), pair it up with an appropriate blade and blade adapter, and see how it goes. If it didn't match up perfectly, I'd get a new BBC system, if I thought the engine had enough life in it. I have boxes full of engine parts, and not all Honda engines (GCV/GSV 160/190) are compatible with all year parts. They evolve often.
But, if my HRC216PDA's crankshaft (GSV160) ever got bent, I'd likely replace it rather than straighten it. Not a big deal. I've got the service manuals, as they're available on eBay directly from Honda. If my GSV160 is ever beyond repair, I'll go to my Honda dealer for a whole replacement engine, as you won't find one anywhere else. Would a GCV160 suffice? Yes, they're great engines, and since I have several of them, I could easily stick one on, but I love my HRC216PDA enough to keep it 100% OEM. And that's the only reason. I LOVE that mower. But, if Honda no longer made the GSV160, and if I didn't have a replacement GCV160 on hand, I might consider going with a GCV190 simply out of curiosity, but I've never found my GSV160 to be lacking in power, and I don't think that has anything to do with the lined cylinder wall or extra bearing. Those are harsh condition longevity benefits. A well cared for GCV will last long.
Now, if were you, and had that GSV190, I'd go to a good mower shop, and do a trade/partial trade for a compatible engine, or engine work on your GCV160. I wouldn't mess with altering a perfectly good engine to make it into something it was never intended to be.
Hope this helps.