727 no 3rd

I have just completed a basic rebuild of a 727 transmission. New clutches seals and gaskets. Every thing looks good and no leaks. : ) Problem is the 3rd gear shift never happens.. The trans shift 1,2 and reverse no problem. 3rd looks like it wants to go at 40 or so then slips into neutral. Slow down a little a back to 2cd. The Valve body is a older Trans Go oddly missing one of the check balls when I inspected. So I begged the local trans shop for one and replaced it. all 5 check balls in plus one the spring and large one. I don't know if the VB controls this function. I can only guess. I am thinking of replacing VB with a stock unit to see if this may fix this. Also the Toque converter is super tight. NO stall engine runs in park and in drive with brake. But it runs like a stick. 1,2 shift is hard and strong almost no tire spin. This car used to spin the tires all the time with old trans and Torque converter. I am just guessing at where this build when wrong. I think the pressure to the converter is way to high. Again I am wondering what controls this. VB? Post any thoughts Thanks.