You need ask what size he wants then you can buy them from any tire shop Hoosier and Micky Thompson make them both good brands of slicks for racing. I'm sure big o tire or leshwab can have them order for you, an example of a tire size is 245/45/r17first number is width second is tire height and third number is rim sizeif this is it these are what you use at track and arnt street legal racing slicks there called and you will need two for power wheels so also know if its fwd or rwd