The bellhousing on a T400 is part of the case. It will need to be cut off before an adapter plate or custom bellhousing can be used. The adapter would need to bolt to the pump. KEAS can do it if they are still around. The cut the bellhousing off and make an adpater plate to fit the T400 to an old EA 3 speed bellhousing which bolts onto an XR6T motor. Not sure if anyone else does it. It wouldnt be too hard for a decent shop to make I imagine. Here's one for a t400 to supra bellhousing.