I have not heard of anyone spending the time to do this but I am sure you can. before you take things loose I would take some timing measurements so you can monitor what happens on with the changes. Personally I think you might as well drop soem cams in there if your going to spend the time messing with it. I know Nev does drop in cams as well as some larger ones that will need to be dialed or at least checked. He will point you in the right direction. Also Carpenter Racing has other cam grinds that are milder then what they put in there kits. You should contact on of these two for some answers. I have a couple in mind for you that might be ok with the stock oem springs but I am not sure if I am allowed to throw numbers out there. Anyway my point is as long as your going spend the time to messing with the stockers you might as well add some lift.
Like I said I would contact Nev or Art ans ask. Both could give you a idea of what would happen if you just increase the LSA a few degrees.