What is the differance, personell wise, between the 3-4 and the 4-3 defense

I love the 3-4, but we don't have the personnel for it. In the 3-4, the front defensive linemen have size and take up blockers, allowing the linebackers to make plays. The outside linebackers are usually the main pass rushers.

Grant is a 3-4 end. Will Smith is not--he's a 4-3 end--and would have to move to an outside linebacker slot if he could make that transition. For a 3-4 defense, assuming Smith could transition to outside linebacker, we would need two more linebackers, an end, and most important a nose tackle to anchor the line.