Yes. It'll be fine, but less strong. I made this recipe for one of my first brews as well. I found the hopping level a bit high for a porter of this gravity. I don't know what formula Palmer is using, but when I plug his hopping schedule into Tinseth's formula I get over 50 IBUs. If I brewed this again I'd probably up the chocolate malt to 3/4 lbs and drop the IBUs to 25.