You're confusing me.
"it shifts hard and doesn't feel like it's slipping. The torque converter feels like it's "loose........ which is it?
Well if it's a 4bbl and a cam, then something ain't right, about the combo.
It shifts into gear hard, not slipping, but while it's in gear it'll be a high rpm and stay there until the speed catches up to the rpm then the rpms will climb.