th400 2nd gear problems

[408stroker]

I have a th400 in a drag car with a fresh rebuild with some upgraded parts to handle higher hp. Off the trailer first time warm up down pit road testing the trans I had no 2nd gear, now 1st, 3rd, and rev work great, now 2nd does work alittle but no where near full pressure like 1st and 3rd, I've heard the sprag could be broke which we put a new better one in, but off the trailer broke already? I was thinking valve body issues since it does work some just not a full lock up like 1st and 3rd. I do have a full manual trans brake valve body from tci in it. A little help or other possible issues it may be will be greatly appreciated.