Swap 904 to 727?

The 69 340K is a valuable item. It's not GOLD mind you. But it should be easy to find a new home for

But you might be doing yourself a favor by trading that 727 for a known to be good 904. You will save the costs of shortening your 904 shaft and finding a 727 yoke. Just be sure to get all the KD linkage with it.
I have done this swap (1975)with early 273 engine brackets and oem rubber mounts.The 340 fit right onto that slanty K. And I had no issues with the early slanty C-link. I even used the 273- 904 with the slanty tri-pot front joint. And I even used the 7.25 slanty rear.
The tranny gave up first. I was 22.