Re-built 727 - No Upshift!!

Hello all, this is my newest issue that plagues me putting miles on my duster before winter. Engine , Rear end and Tranny have all been rebuilt, and the tranny in particular has been built by a reputable builder in my city, but installed by myself when i put the engine in. Here is the Issue. The tranny goes into P-R-N-D ETC..., But when in drive, it does not shift out of first gear. When shifted manually, it will not go out of first gear either. I can get her up to 4000rpm, then let off the gas because it woun't shift, then if i give it gas, it sounds like it is just reving and not in a gear...then if i manually down shift to first, it kicks down. Is there a pressure issue in the tranny or do the bands need to be tightened or has anyone had this issue.?? thanks.

SG