I typically run a 4-3. I also run a 3-4 at times which is why I run the Ravens Defensive playbook. As for the 4-3 defensive, I need a LE and RE. I've ran with chase young and 95 reggie white. They did great for me but seem to be falling behind a bit. I upgraded to TOTY Aaron Donald and John Abraham but they barely generate pressure. I move them around, shift the line, etc. but nothing really.I still have Sapp on the inside with his light it up token and he gets way more pressure.

Out of experience  that you have used, who do you think would be the best  defensive ends in a 4-3? 

Appreciate any advice.