Unless your gearing on the FG is too high for your current fitness level or local terrain the most imp determinant will be your aero position on each bike (or lack thereof).
If you stretch enough so you can rotate your lower spine forward vis a vis your hips and your bike fit allows you to stretch your torso forward enough to get a flat back, then all you need to do is hold your bars near the stem and keep your knees in and you can punch a cleaner hole through the wind.
Gerry