65 dart 318 swap- manifolds?

Im trying to put this worked 318 out a 69 satelite into my 65 dartgt which was originially the good ol slant.

Of course its a puzzle getting it to fit/work.

I got the custom motor mounts from schumaker.

So its all good and gravy that the engine can be installed and sit in the bay but wait.....stock 318 exhust manifolds bring to my attention one of many issues ill be dealing with. They dont clear the stearing column.

Ive been told the 273 manifolds will fit so believe it or not i found a set.

The stearing column is no longer a problem BUT now the passenger side seems to be a problem. Hits wheel well and the port goes directly into the motor mount.

If i were to use a stock 318 on the passenger side and the 273 on the driver side (wich solves the fitment issues) is that a bad idea and will it afect the performance or be bad for motor?

The 273 manifolds Im told are better for performance? They look better being they are much more hollow and larger inside.

THANKS!