383 or 413 advise

Hey All,

I have a 69 383 B motor complete that i am planning on putting in my 68 Valiant. It turns over freely and has good compresion but I do not know the history.
I have been having a hard time tracking down a BB-727 for it. I did not get the flex plate with it so I was hoping to buy a tranny T-converter and flexplate that came together from the factory so I know they will all work on the first shot.

I found a good running 413 from an unknown year motorhome that comes with the 727 behind it. 100 bucks for the whole set up. I want to purchase this so I can use the tranny, t-converter and flexplate.

My question is will this transmission/flex/t-converter bolt up to my 383? Or would the 413 be a better motor all together.

Any advise is much appreciated

68 Valiant