what size sprockets?

[honduh440]

i have a 440 with every internal mod done when ridding motocross with 18 inch rear tires and 20 in the front what is the best sprocket set up for the track?

[ss440ex]

I played some with the gearing for mx and I
like the 15/38.
I also have the 440 with 18 rear.
Dressed body weight 225lbs.
Works good on setting me up for doubles.