I was wondering if anyone knew what a stock 2000mustang 4.6 block would hold up to horsepower wise. Also what is the best way to build a 4.6 with out changing the factory block so that the bottom end holds up to maybe a supercharger down the road. How much will an upgraded throttle body and plenum get me.

 

the stock block will handle a lot of HP, i think more then 400HP before you've got to worry. every block is different though, and milage counts for something. what you've got to worry about is the crank and internals, make sure they can handle the power. as a matter of fact, i would upgrade the whole foundation of the car: drivetrain, brakes, suspension.

as far as a tb & plenum, u might get like 14 hp, but depending on what you have done already, it'll be a waste.

 

Blocks good for 600-700rwhp I can't remember exactly, but its a solid chunk of power. internals are good till 420rwhp rang then I would worry above that.