First the Curado is a fine reel. I like Power Pro Spectra braid for lots of lures. I usually suggest 20 to 30 pound braid at most. The thing about that braid is 20 pound test PP is only size of 6 pound mono and 30 pound PP will be the same size as 8 pound mono. So I like the thirty pound line for most baitcasting situation. Let me know which Power Pro product you have spooled up. I also always tie on a backing to my reels. So I will buy a spool of inexpensive but quality 14 pound line like Stren Blue, or Suffix Elite, Bass Pro Excell, even Berkley XL. There are tons of good quality mono or copolymer lines that do not cost an arm and a leg compared to top quality braid and Floro. Make sure you tie the backing on with a good tight arbor knot. If this not slips the reel will not perform correctly, this can mess up casting and the drag system. Once your spool is 1/2 full then tie on, using that dreaded uni to uni knot,(it really is an easy knot once you use it a bunch) the braid. Make sure you fill the spool up enough, but leave about 1/8 of an inch of the spool exposed. This will work best. Now instead of throwing the light weight crankbaits I want you to tie on a 3/8 ounce jig with any kind of plastic trailer, like the Berkley Havoc Pit Boss or Strike King Rage craw. The weight of this bait will be in the middle of the weight the rod is designed to throw. Take this to the lake or cast it in the back yard. This will give you the confidence with this rod and reel. That jig and trailer will be able to load up the fast action tip very well The 734 is a terrific rod but it is not designed to throw light weight crankbaits. I want you to look at the Dobyns website. Look at the Champion rods You will notice as you scroll down there is a DC684C casting rod. If you read the description, both lure weight and suggested lures techniques, then read the same info on your DC734C rod. They almost match. Drop down further and read the info on the rod I am suggesting, it is the DC684CB. It list the rod as a Medium action rod with a moderately fast action tip. If you put the tip on the ground and gave some pressure to the tip it would bend the rod much further down the blank towards the reel seat. Light cranks need to load a rod more for distance. These rods are like a mechanics wrenches, I need a 1/2 inch wrench and a 3/4 wrench , they will not do the same job even though they are both wrenches
There is no reason to spend money to replace the Spirex reel, it is a fine reel. My wife and I have gone to braid and a 10 pound leader on all of our spinning rods In case you are wondering the combination of braid/ copolymer leader has caught us some huge stripers, catfish, and bass. So just fish that combo. It is perfect.
I want you to do something with your Corado before you cast it. Tie on the jig and trailer. Now unless that is a new "I" series you will only have the spool tension knob and the centrifugal brakes to adjust your reel with. First loosen the spool tension knob until the spool will move from side to side with your thumb on it. Next slowly tighten the spool tension knob up until the side play is just gone so adjusted like this your reel is as free as it can be and set for its longest freest casting. Next open up the side plate and turn on all of the brakes. Now with that all done push the thumb bar and watch how fast the lure drops. If it really rockets down to the ground you may need to tighten down the spool tension knob a little more. A s you get your thumb educated we will want to free up the reel a little more by dropping down the number of brakes turned on and then gradually loosening the spool tension knob till there is almost side play or just a tiny bit of side play. Make some casts but make sure to use your thumb to slow down and stop the line at or near the end of the cast. It is a learning curve, but you will gain confidence and distance with some practice. Fortunately practice can be done on a kayak and is best done with plenty of "interruptions"
Last one what would I to finish up the Dobyns DC684CB combo with. Well I am torn here because you already have two Curados. Let me ask this first. Which model Curado do you have on the 734? Is it the new Curado I series, a Curado G series or an older Curado E series?