Sluggish 904 when cold or converter?

Either the trans with the Cheetah is a real tight trans or it the Cheetah VB fills in park, or maybe both. The Swinger sounds like most without the mod. Parking them on a upward hill makes them even worse. I had a 93 Dakota with a A518 and by the time it had 70,000 miles on it it was starting to drain back. Parked it on a steep hill once for a couple hours and it took it every bit of 45 seconds to fill the converter

naw i put the trans in N to fill it, ive started it and idled and dosn't fill. the trans was rebuilt not that long ago and maybe has a hundred passes and 5K on it. all stock internals just clearanced, except for the VB and converter... though i think im going to either go 200R4 or do the small block guts for better holding.