HELP PLEASE th350 shift problem

Last year my muncie died and I had A th350 rebuilt and we put it in my 78 gmc truck. The problem is that when I put it in drive it shifts from 1st right into 3rd. When I am almost stopped it downshifts into 1st. NO 2nd! I can however up and down shift through all three gears fine with my B&M shifter. 1-2 shifts ok too if I leave it in 2. I have put a new B&M modulator on it and no change.I want to get the governor kit but not sure if that will work either. can someone please help with some good advice?
Thank you,
JIM

hi you have intermediate sprag failure when you shift manualy the second band holds the direct drum.when you let the trans shift the intermediate clutches hold the sprag which holds the drum .If the fluid is burnt you lost the intermediate clutches anyway it needs to come apart.

thanks for the info guys. So the guy who rebuilt it must have screwed up and put something in wrong then? I have no warranty and the guy who did it is gone. Hmmm.Will I have to get the whole thing rebuilt or just the valve body?
Thanks again.