I don't remember. It was actually mine when I did the trans. That was 5 years ago. Might have been dex 6 or regular dex 3 ATF. If you plan on running it hard id consider low viscosity hy-gard. Dex 6 is a good longevity hyd oil also. I run hy-gard in my own cars but they are raced. I've made quite a few updates to the calibration and use some different parts these days. I do remember the trans having a good forward drum with an aftermarket shaft though. If you want me to do all the updates I can do them including removal and reinstall.