Flipping - Maximize Appraisal

[Galen Dawes]

I'm renovating the entire house. 4 bd, 4 ba with basement. The roof has fairly new architectural shingles. I will be replacing gutters, shutters, front door and garage door, stainless steel appliances, cabinets, vanities, countertops, inside doors, back door, new grass and landscaping, new fence, new tile in bathrooms,acasia hardwood in kitchen, foyer and master bedroom, all plumbing fixtures, all missing copper pipe with cpvc, door hinges and handles, toilets, adding double trey ceiling in master, granite counters, painting inside and out, new carpet, adding some crown molding in master, kitchen, foyer, family room and master bath. The ac units and furnace are old but in good working condition. I normally leave the original ac units and furnace if in good working condition. I will replace the water heater but do you think it is necessary to replace the ac units(2) and furnaces(2). How much is that going to add for the appraisal value? The other highest comps in the area have old ac units and furnace also. Without adding sq ft, what is going to give me the best bang for the buck on appraisal value?