It's probably easier and cheaper to sell the 30/06 and buy a SPS. For under $100, you can get a BDL kit (Brownell's has them). Then you will have to modify theADL stock for the floorplate or purchase a BDL stock. Should be able to find a used one for $35 to $50. Converion to a .35 Whelen will involve, at the minimum, an aftermarket barrel and labor. Say $300 for a Douglas barrel installed and blued. Could spend a lot more for a barrel, but probably not warranted for what most people would use a .35 Whelen for - hunting larger big game animals.