Blown alcohol small block?

Correct on the fuel (especially methanol, but within reach with enough boost on e98) being able to produce that much power, given you have a strong enough vessel to contain the pressure. It’s not just the extra volume of fuel that you burn to a given amount of air or oxidizer. It’s the longer burn time making power for more degrees of crankshaft rotation during the power stroke. The going rate for top alcohol classes on the drag strip is approaching 3500 horsepower. Not bad for 500 or so cubic inches. A good place for a sleeved cold weather 400 block with grout and BCR cap and girdle system.