I don't think you'd notice any difference between the original cam and the 300HP cam. Probably the same cam, if you're talking factory cams.
If you want a little more cam, you might want to try the 350HP cam. I think the last 3 numbers of the original 350HP cam were 151.
It'll give you a little bit of a lope, but is very streetable, especially with a 4 speed. Or you would get about the same effect with any of a number of more modern grinds, such as any of the cams mentioned earlier.