Actually I tried, it's possible to do it with that launcher, with a very agressive flying technique. But with what you had left of fuel in LEO, that was too low.
Moon's advice is good, I would also transfer some fuel from the first stage to the second stage (let's say 15 tons) to get a more balanced rocket.
Then it's all about your flying technique. As you have a good TWR, start building your horizontal speed as soon as possible. Don't be afraid of flying at high speed in the atmosphere, the air pressure decreases very fast: it halves every 2000 meters. At 10000 meters it's only a bit more than 3% of the ground pressure. Your ship is very well shaped anyway, so don't hesitate to use a very aggressive trajectory. With all this the victory should be yours
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