Correct 340 exhaust manifolds 1970 duster

I've located a pair of orginal exhaust manifolds, that have the following casting #'s
Driver side?- 2863548 - where as parts books shows # 2863545
Pass. Side - 2863553- " " " '' # 2863552

I've been told that the 68-69 70 exhaust maniflods are same as unique.

My ?? is will the ones I've found fit the car?
I'm trying to finish up my son's car as he had headers "black jack" and they are hammered and bent and not a whole lot of room to work on starter etc.
He died of cancer 8 years ago and i want to get car ready for his buddy who helped him as i'm going to give it to him..

thanks.. Pdust70 something that fun to drive & no trailer queen.