Technical 8ba fuel pump

New on flathead motor, i have a 8BA that need a rebuild and i will modify in a 59A, now my question will a 59A fuel pump mount or need anyway a 8BA fuel pump? I was thinking to mount a Blackstone fuel pump which one is the best option 59a or 8ba pump ?
Thanks

 

If you use an 8BA intake then I’d say use the one for the intake

 

I'm using a slingshot made for 59A

 

You will also need the correct pushrod for the pump you choose to go with, they are different lengths.

 

8ba pump rod is thicker too. Not sure this mix is a good thing

 

Yes the early one is .370" diameter and the late one is .430".