360 stroker kit in 340

The Magnum cam will work. I put a hydraulic roller in my 273 that was ground on a Magnum blank. If you're going to run a mechanical fuel pump, you will need to buy a cam snout extender from Hughes. Magnum cam snouts are shorter than LA cams and you can't bolt the fuel pump eccentric on without the extender. If you gotta buy a crank, you might as well get a 4". 416 CI will be better than 372! Just make sure that Magnum cam is up to the task of a stroker motor before you plunk down the money to buy it.