Tuning Texan 357 change to CF tank?

I kinda regret buying the 357 Texan. I'm not impressed with the power. 300fpe is like eh. I get 295 with 174gn slugs. 3 good shots, 4 a little slower. 82gn is 200fpe and 10 shots. Not bad. But it's so damn long. I noticed Airforce is offering a CF bottle / valve upgrade for the older .45's. Can you swap the 3k bottle with a 4.5K bottle and fill to about 3600psi keeping the stock valve to get a little more power or shots? What's the max psi the stock valve can handle with an upgraded spring? I bought this new, so selling it would be a big loss.

The new 45 Texan with CF bottle TX2 valve is what I should have bought. Too late now. It's not worth upgrading everything with African Air Ordinace parts. Might as well just buy a new gun at that price.