Well ideally, you weight them-- but as i recall Joy of Cooking (great cookbook) has a guide based on USDA grade size-- (x many medium eggs = 1 pound, y many large, etc.) If you are in a more rural area you might have a coopprative extention office of USDA, and they should be able to give you a clue-- I think for pound cake its 7 to 8 USGrade A large eggs to a pound--more if using medium, fewer if using extra large or jumbo eggs.
pound cake can be made by creaming butter and sugar, adding eggs (in about thirds)beating well after each addition, (adding vanila or lemon flavor) and adding Flour in thirds. (fold in last third) No levening is needed. the air in creamed butter/egg mixture is all that is needed. (Joy suggest 1/4 to 1/2 teaspoon of double acting baking powder as a back up) Turn into greased and floured tube pan, back at 350 (F) for about 45 to 50 minutes.. Until done (check with toothpick)
