904 stuck in low

Haven't looked into it to far yet, but was wondering if anyone has seen this before. 74 duster slant six auto. Driving it up the hill by my house i manually shifted it to second to keep it from going to third as it always wants to but doesn't have the power to pull. Anyways topped the hill went to manually shift back to drive and it wouldn't shift. Got home, shifter stuck at second, can shift first and second. Popped the linkage off the transmission and the column shifts fine, but the lever on transmission won't go past second. What did I break?

Remove the NSS (you'll lose some fluid) and see if that frees up the shift lever. If it does, the plastic shoe on the rooster comb may have broken and is jamming up the works (if it's a '71 and later).

Thanks for the reply. I finally took a look at this tonight. Of course, I crawl under it and it shifts fine through all the gears. I played with it a few times and it jammed up again this time it would shift fine from park to neutral then wouldn't go into drive. Popped the switch out and looked through the hole, the plastic is intact. Dropped the pan, and moved the shifter through the gears. It appears the clip holding the park rod is broken and it spins around sometimes jamming up against the valve body. Would this be the same setup in a small block tranny? I have a few of those lying around. What a weird thing to break.