Isn't that a little large to stroke a 351? over 100 cubic inches? I would worry about durability myself, but then I guess if you barely ever drive the thing it would be alright, I have to say for that price though you could build a big block(460?) nicely(which wouldn't fit I know, unless you got a mustang II front end, or possibly an RRS notched shock tower+ coilover kit, either of which you could afford after building a big block easily enough...you would still end up with the torque you want with an engine that would be a bit more reliable(and an upgraded suspension to boot, if you went for the RRS stuff) that being said I understand you probably dont want to cut up your fastback to fit an engine, so I understand why this engine would appeal to you....there is always the other option though...build and turbocharge a 351w instead...you will still come out cheaper w/ the same power, plus better reliabilty and gas mileage(as long as you arent under boost anyway) or supercharge one for that matter
I guess I consider 13k too much to pay for an engine(thats four times the cost of my project so far, including engine, tranny, rear end, suspension and the car itself)