545rfe ?s

There is a thread on here for one of the new solenoid shifted transmissions, maybe this one. Some guy swapped one into a Chevelle, and designed his own controller. As I understand it, he GUTTED the stock stuff in the trans except for the bare solenoids, and connected direct to them. Sounds to me like you need some timing to release one and apply the other, hell you might be able to do it with "relay logic" and 2 or 3 adjustable time delay relays. That would give you full manual control, at any rate.