… with about 4300 hours …

I change my oil & filter every year or every 100 hours, whichever comes first;
Change my ATF every other year or 200 hours;
Try to clean my Fuel Tank every 5 years
Change my primary & secondary fuel filters once/year;
Clean my Injectors & adjust Valves every 500 hours. Injectors are due for a rebuild, which I hope to have done this year. Annually I do a SeaFoam bath for 24 hours;
Change my ALT belt every couple years;
Coolant Flush every 3 years;
The last time I had my Heat Exchanger pulled and cleaned was 2000 hours ago;
Every 1000 hours I pull my Elbow and clean that;

That's all I do. Cheers, John