How much horse power can you get out of a 302 small block?

It's stock, coming from a 1970 ford mustang fastback

Probably 400-450 with the stock block.Past that hp level you're safer and better off to use a stronger block like Dart, A4, etc. A supercharger or stroker kit is the quickest and easiest way to get into the higher hp range. You can bore a 302.030 over and add a 347 stroker kit and you'll have 347 cubic inches. If you buy a stronger block and bore it.060 over, you'll push it up to 363 cubic inches.Don't bore a standard block more than.030 over because doing so will significantly weaken the block and the engine will also overheat due to having such thin cylinder walls.A Dart or Motorsport A4 block has a lot more material and areas such as the mains, lifter valley, and cylinder walls are much thicker and stronger. This block can effectively be bored.060 over without creating any ill effects. If you're planning on using stock components primarily, the 1969-1971 351W head is a great upgrade if you're not planning on installing aftermarket heads.Has 60cc chambers(ups compression)bigger valves too

With performance parts, around 500hp naturally aspirated maximum, 750-900 with a supercharger and over 1000 hp with a turbo. Stock it's probably less than 250 hp.

300 would be a lot, probably 200 stock. If you want a lot of power, consider a crate 351.

The 302 in the 1970 mustang is a clevland not windsor. And is a destroked 351. The trick to getting these engines to make power is the cylinder heads swapping the 2 valve heads for 4 valve heads. Or buying some 3 valve heads from chi in australia. Parts for these are starting to get thin on the ground.

the fastest clevland powered cars are in australia. They can be stroked to 378 ci it has more torque than a windsor, there was a drag car in the 6s run buy a guy named brendan mc sweeney. In his ford falcon.

in standard form about 2-300 with the usual mods, exhaust and carboration change but 750 -800 with more extensive mods.

if you want to go faster, expect to be hunting on the internet.