I hope you plan to replace it with something, there won't be anything keeping the front end from folding in on itself once the front crossmember is gone. It will tweak the front end as soon as you cut it out with no bracing in place beforehand.
You'll benefit more from moving the engine rearwards and cutting the firewall out than you will by having it further forward. The less weight you have forward of the front axle's centerline the better, it will help keep the nose up when you're hauling ass.