The DZ 70 is a really strong running engine, I havent ran one with a 14x7 but thinking the rpm will be around 8,800 or so on 20%. I will try to run one this week for you to see ok. The FZ-80 has more power and the engine I would go with but depends on your plane set up and how you want to fly it. The 80 has 3mm more stroke to it. I do know the DZ-70 will spin an APC 11x14 at 11,000 on 50% nitro.

I forgot to add but I run the 14x7 on a FZ 80 in my hanger nine christen eagle but I never tached it. I am thinking it is around 9,500 or so on 20% but not 100% on that number.