What year bike and where are you located??
- Some of the older LS650's had slightly different jets.
- Altitude and humidity also affect jetting.
But.... I think the 52.5 low might be better and if you'r running the louder HD muffler a 155 main may be closer to what you need.
Sorry, the best advice I can give is to experiment and to keep an eye on your sparkplug color. If the Ceramic is white, you're running lean. If it's black you're running too rich. It should be slightly tan in color.
Also, the perfect low speed jet should allow you, when adjusting the low speed /idle mixture, to get a reaction on both the lean side ( turning in) and on the rich side (turning out). Only problem, sometimes and conditions, the perfect low jet is in betweeen the ones you can buy