big pit with coned spool supposed to be the best for distance they will add some distance as their is less friction as the line leaves the spool how much extra ? hard to say reeley

the extra yards would be gained with better casting style a trip to slaughter hill with the casting lads could be alot cheaper than a new reel

if your doing something wrong and you remedy it you could add 50 or 60 yards to your cast in a few hours of help from the lads,then again a nice new reel would look good on your rod too