I had my radiator re-cored ,installed it, topped off the tranny with fluid. Took car out for a little test drive. Decided to do a burn out ,thru 1st and 2nd . Came up to the stop sign and when I took off it acted like it was still in drive. Tried it a couple more times from a dead stop and it does the same thing. Although it shifts fine when you manually shift it from 1st thru drive. What could be the problem ?.

overrunning clutch(sprag)

just guessing,as i dont know how to fix them,just tear them up and change them

but i have had that before and it was not good,hear any noise when pulling off in drive?

not wanting to work,pull it down to 1st and it grabs and goes? shifts fine manual shifting,up and down?

got one on the shop floor like that myself,works but makes noise when i forgot to manual shift it after a stop but works when shifting it up or down just no auto function

One of the Governor weights is sticking. I had that happen lots years ago when I was sometimes too lazy to go thru the governor support and weights on a quick rebuild.Not anymore!
You might be able to get the extension housing off and take the weights out and use some crocus cloth to clean them up.Then flush with a cleaner.
Definitely a "debris" issue though.

3rd vote on the governor. Get an A&A gov weight while your at it, just pick your RPM and leave it in drive - best thing since sliced bread

Thanks guys, I will check that out.

Before tearing into anything but a pressure gauge on the governor test port, anything over 2 psi at a standstill in Drive is a governor problem.

If the pressure is OK look for a stuck shift valve in the valve body.