turbo350

I have a turbo 350 in my dirt car ,just rebuilt,when I race it after about a lap it starts spitting fluid out of the little breather hole on the top of trans. Is this because of to much fluid or something else.The dipstick shows full.Otherwise it works great ,also we do not hookup anything such as vaccum lines kick down cable ect. Thanks for your help!

Sometimes overfilling it causes the fliud to aerate, or foam up and do exactly what you say. Try draining out 1/2 quart and see if that helps.