IMO I would get the 80FZ. It has the pressurized fuel system and easier to run. The DZ is strong but in the 70/80 size it is a little more finicky to tune. I will someday run a 70FZ on same prop and then a 80DZ and then a ignition on all of them. The 80 is hard to beat for the power it makes with a weight of around 18 ounces. You maybe able to run less oil but I wouldn't do it. The oil does add to the compression some. I have run up to 55% nitro in mine and run 60% in my 115WS engines.