I'm just here so people can get #triggered about me coming within a square mile of a thread that utters the word comanche LOL.
Joking aside, my answer is:
neither. Get a C33A or newer equivalent. The -A suffixes are IO-520 285HP variants of the same airframe by the way. Personally I would get a G33 (260hp IO-470 from the factory) if you could find one. An IO-470N modded C33 (whereas stock is 225hp 7:1 CR cylinder IO470J/K) is the same airplane but you cannot legally bump the MGW, which makes it a limited upgrade imo. The G33 came with the legal increase from the factory. To be clear, the -As have higher MGWs than the 225hp or 260hp equipped ones, as one would expect.
I used to feel strongly about the differences between getting into a -520 vice -470, or hell even tsio-360. I no longer feel that way. They're all equally likely to chunk an exhaust valve and ruin your day, as they have members of this forum in the recent past. So the added hassle of the 520 chunking the alternator gear doesn't really keep me up at night in that context anymore. Ditto for a spun starter adapter eating your steak dinner money, or a VAR crank expense, or turbo ducting woes on the tsio. You either buy into it or you don't. On the Lyco side, Comanche 250 chunked a camshaft in cruise two weeks ago out of the blue, and I considered that engine bulletproof. Bottom line, engines are sunk costs in this hobby. Get a chute or a second engine, if that's what you're worried about regarding the whole "
which would you put your family in?" question. I've yet to have a power loss on my Lyco O-320 (prior) and IO-360 (current) respectively, understanding these small mills are not apples to apples to the performance of the 250HP+ birds you're talking about. BL, I consider powerplants the real achilles heel of this hobby. I rationalize my choices within the limitations of the hobby, or I exit stage.
icky news? Hope nothing's wrong with your current ship.