Milling the Heads How much?

I was more or less on the same road you're are now except my engine was a 273. I had already had the "302" heads cut also back cut valves. I still wanted more torque/hp but the 273 was already bored .060 so that was that far as the engine. I had a friend make a suggestion that made a since so I did it. I bought a blueprinted 360 short block and never looked back. The longer stroke of the 360 made a big difference. The total cost was $900 the cam bearings was already installed so I installed my MP .474 cam, installed my small valve 302 heads, performer intake, carb, etc... off the 273 engine and off I went. Just a little suggestion that I will more likely get flamed for but it beats the hell out of a short stroke 318. lol