The Mustang is among the coolest of all American vehicles, so you don't have to worry about this one. As for speed, it's been the fastest of all American pony cars since the year it started production, and it has power to back it up! One of the best Mustangs of all time was the BOSS 429. This is a very expensive and rare one to buy, but you don't have to buy an actual boss to get the power of one. The following site: ( http://candcmotorsports.com/ ) offers a Boss 9 engine, the NASCAR variant of the engine, with hemi heads. Buy it, get all the parts for it, and construct it yourself, or have a mechanic do it if you don't know how. If you go to http://store.summitracing.com/partdetail.asp?part=SCA%2D946045&autoview=sku, where you can get a 4.5 in. crank, the buy a 6.7 in. set of rods to match, then get a local garage to bore it to 4.8 in, making it an overly large 651 CID engine, which would be extremely powerful (although expensive), but that's just what I think you should do. It'd be something big to brag to your friends (and enemies) about. Well, good luck, and if you can't afford what I advised, don't sweat it; 1973 ford mustang's are top notch vehicles anyway!