Mastercrap tires? Run away. Daughters Exploder came with them and they were horrible. Bought a new set of Michelin LTX's for it and the difference was so noticeable my stereotypical blonde daughter even commented on it. The Mastercraft tires probably had half the tread left, dunno how old they were as it came witht he trucklet. So, YMMV, maybe they make them better these days.

I'd go with the Michelins if you can swing it myself.

Don't forget to recalibrate the speedometer is you change tire diameters in the back, usually it's a gear change in the trans but I dunno your specifics.