I’m with Thrownchain. Bottom end rebuild kit with seals, bearings, gaskets and new screws. A piston kit for a top end rebuild.
If you’re not sure what size piston to go with, look at the top of the current piston. If it’s not got a size stamped on top it’s likely a std piston. If it’s std or .010, determine if the next oversize is appropriate. If it’s a .030 there’s only one bore left in it unless you can find bigger than .040 pistons & rings from someone.
A piston kit should have all of the following;
Piston
Wrist pin
Wrist pin circlips (2)
Top rod bearing
Lower cylinder gasket
Head gasket
Intake manifold gasket
Exhaust gasket
Also check your oil drain plug. Make sure the compression washer is still good.
And, unless it already has the upgrade, get a heavy duty kick shaft bearing retainer. The OEM retainer was pretty thin walled.
Then have the cylinder bored to match the piston and rebuild the bottom end, replacing the bearings, seals & bushings. Order a couple of countershaft sprocket lock washers too. And the counter shaft O ring for the inner shifter case cover.
Bead/ball blasting or vapor blasting will improve the looks of the shifter cover, cases & clutch cover as well as the cylinder, head & intake manifold.
And make sure you have all the parts needed to rebuild your carb. Main & pilot jets, O ring seal for needle valve, the correct needle snd a hood needle clip and confirm you have the correct slide. Also clean, inspect & replace the float needle valve assembly in the carb, snd clean the choke snd it’s passageways. Check where your air screw is set compared with the published norms in Terry’s library for your model motorcycle.
Depending on the exhaust manifold, you may also want a new exhaust compression gasket if not a slip fit exhaust.
Best of luck with your project and keep us posted with questions & progress!
http://Hodaka-Parts.com should have everything you need, from engine & tranny parts to cables & levers! Purchase on line at the website or Call Terry between 10 am & 3 pm Central time!

Victor