2 heavy muscles gilts. They look great. 220 lbs with 42 days to go. Max weight 280. I would like to trim some neck fat. Can I use 709 and fitter 35 for 14 days for 1 lb of of gain a day then recalculate what they need to gain? How much of each?

The best way to gain 1 lb per day is:
(Total daily feed; divide into 2 equal meals):
High Octane Powerfill. 3 lb
High Octane Depth Charge. 1/2 lb (8 oz)

You can clean up the front end and put on muscle shape the final 14 days by feeding:
(Total daily feed; divide into 2 equal meals):
HSC 719. 5 lb
High Octane Fitter 52. 1 lb