Birthday cake?

can you put sour cream and half and half in boxed yellow cake mix? I had made one with cake flour and it came out good, but this is premade mix, will it still turn out good? I making A 5 YEAR OLD GIRL a bday cake. thanks

The sour cream will make it more dense. I suppose the half and half will too. I say go for it if you can find a modified recipe and know what the measurements should be.