Reguardless of what it runs, i'm happy to see that you are moving up, and starting a little slower for him to get used too driving the big car from JR dragsters, so many of the top driver of today got their start in the JR's and it's a perfect starting point for kids, if i had any at home of the right age i'll guarentee you i would have them in the JR's.
Good luck and keep on keeping on
Zip