I also target 50/50 Port to Venison usually using Shoulder for more fat content. I actually buy ground Fat in case the Fat content runs too lean. Make sure you trim the fat off the venison before freezing. I use a vacuum sealer to minimize air exposure. Air exposure when thawing seams to increase the gamey flavor. Trim the venison again where necessary, especially dark and bloody spots. I thaw in the vacuum bag to further minimize any gamey flavor. Grind the pork and Venison together with seasoning and your good to go.