ThunderSlot Axles and Bushings

I worked on a ThunderSlot Lola this afternoon, trying to go beyond the obvious things to do to an out-of-the-box great car. I wanted to try different gear combinations to see if I could improve something.
When wanting to replace the rear axle and gear, I was surprised to see that Slot.it axles don't fit in the rear bushings (the bushing's opening is too small). I tried another pair of ThunderSlot bushings and I got the same result.
After some research on the web (and on HRW), I can't find any reference to this. Was someone able to replace the stock axle by a Slot.it axle (or any other 3/32" axle), using the stock bushings, on the ThunderSlot Lola?
And which combination of gears (diameters and brands for pinion and spur) did you use for the best mesh? I'm curious to know what was used to change the gear ratio from the factory one. Thank you.
When wanting to replace the rear axle and gear, I was surprised to see that Slot.it axles don't fit in the rear bushings (the bushing's opening is too small). I tried another pair of ThunderSlot bushings and I got the same result.
After some research on the web (and on HRW), I can't find any reference to this. Was someone able to replace the stock axle by a Slot.it axle (or any other 3/32" axle), using the stock bushings, on the ThunderSlot Lola?
And which combination of gears (diameters and brands for pinion and spur) did you use for the best mesh? I'm curious to know what was used to change the gear ratio from the factory one. Thank you.