Engine running hot after timing change

[Black70c10]

So, my sbc was set at like 19 degrees BTDC because I had experimented and at one time decided that it ran best right there and had the least amount of bogging. My accelerator pump is fine (rebuilt carb) and so whenever I felt like I had bogging at WOT, I would adjust the secondaries and usually this helped..I run supreme gas and with the mechanical radiator fan, this truck cruises all day at 190 degrees and maybe slowly approaches 200 if its sitting for a while...

For some reason, the thing started to bog at WOT all of a sudden and adjusting the secondaries did little to nothing so I thought I'd mess with the timing again. So, I dropped it from 19 to 15 and seemed to have no effect. I then dropped from 15 to 12 and bam, under WOT it had very little bog. Only now, as I'm sitting at the red light, it's climbing to 220 and looks to be leveling out at 225! When I start cruising it again it only drops down to like 215...

I think I understand why it's hotter-more compression as its igniting closer to TDC thus more heat? Not sure how I can get this thing to avoid bogging at say 15-17 degrees BTDC so I can run it cooler. Help is appreciated