How many using an A500 overdrive ?

I'm buidling an A500 currently to replace the A518 in my Dart.
Id rather go the other direction

That said I have a 500 sitting here that I'm debating on whether I want to put in my truck behind it's /6... I have the adapter plate I'm gonna need to adapt the small block trans to the/6. The debate rages because originally I was happy to have a factory 727 in it behind that 6. I haven't had any luck over the last 40 years with any 904 I've had in any vehicle I've had one in. Whether /6 or small block. And I know that the 500 is 904 based. I bought a Dakota for a few pieces and parts I needed for my 96. It's trans won't work since my 96 is 4wd and also 1st year RE series trans.
But I couldn't let it go over the scale so I saved it when I parted that Dakota.
I like the lower 1st gear idea, but being 904 based like I said I don't have luck with 904s.
If I do use it it will be rebuilt and upgraded anyways I can. Thinking mild shift kit, ( I like the TF-ODjr on my 518s) extra clutches if possible and sonnax billet servos and accumulator.
The other fork in the road is I also have everything needed for a 727 to 833 od swap in hand, too. U was all set for that until I practically fell over a /6 and 727 combo that has the adapter plate is need to put that 500 in the truck instead... Confusion..... Decisions...