When you stomp the gas from a stop you mean? If so first thing you should do is check thr transmission fluid level per the owners manual. If that is fine, and you said everything is stock other then the shift-kit, you will need the style of trans pan found on the '96+ 4r70w's (this is what your transmission is called, by the way, its a form of aode) It looks like the pan on your trans, but it has a hump on it. Using this pan will also require the deep sump trans filter
Pan
'96 style (no drainplug) - F6AZ-7A194-A
'98 style (drainplug) - F8UZ-7A194-AA
Filter for both styles - F6AZ-7A098-A
If it does this while driving, it maybe the mlps, but don't quote me on this, because it probably wrong
