The Penn 113 4/0 fishing reel is slow, heavy, and the drags are weak as compared to modern standards.  In the stock version the line capacities are as follows:

650/20 Mono
440/30 Mono
370/40 Mono

Three  versions of spools came out for the reel, two stainless steel and heavy, one black aluminum and better for casting.  The main gear on this one is steel with a steel pinion.  A single dog is standard with a brass gear sleeve.  Drag is rather weak considering the size and capacity of the reel.  Gear ratio is 2:1

Here is the build list to convert it to a narrow “Grouper Special”

1.  Source a Long beach 66 Spool
2.  New “Tank Top” and base from Ted on alantani.com
3. Gears 2.5:1 from
4. Pinion from 66
5. Drags from Smoothdrag.com
6. SS Dogs from Keta on Alantani.com
7. SS Gear Sleeve Alan Tani
8. SS handle from Motive Fab
9. Knob from Pro Challenger

This build will improve the gear ratio, narrow the 4/0 width, improve the strength, and improve the drag.