KTM 350 SX-F vs KTM XC-F - engine differences?

Hello

The engine is mostly similar in between the SXF and the XCF, biggest change is the primary transmission gear ratios with longer ratios on the XC models. Mapping should be different as well.

You can't compare the gears from the EXCF model to the XC as the engine is very different overall. Different cams, piston, rods, ECU, gear ratios, etc… So you could put exactly the same secondary gear on these two models and have totally different feeling and characteristics. 
 

Hope this might help you a bit 

Never been around KTM four strokes much, but it's the same with the two strokes. The SX and XC are more similar, engines are about the same except mapping and I believe the XC has a little lower compression. The XC had a little wider transmission but it's similar. Then the XCW is completely different from the motor to the transmission, better suited for trails and enduro. I would assume it would be the same case with the 350's. 

the SX-F and XC-F engines are exactly the same, Same transmission too. Only difference is mapping. I have both, 2024. The rear sprockets are different by one tooth, transmission gears are identical. Now the 450 XCF-W is different, 6 speed, more mellow motor for many reasons, but to answer your question, there is no difference. 

2025 XCF will have spring forks, the 24 might have as well. They have quick shift on the 25 has well. XCFs have a 6 speed, 18inch rear wheel, bigger tank, and kickstand. 

Double check but if I remember correct from my research looking for a '23 model it depends on engine size.

XCF is a 6 speed on the 350 and a 5 speed on the 350 SXF. I think the 450 XCF shares the 5 speed with the 450 SXF model.