Hot Rods What engine might have used this mount layout in a 32?

I appreciate that a number of y'all are following my thread on my 32 cabriolet that was in the same family for 75 years.
I thought I'd reach out to the whole gang to see what y'all think of engine would have used the present engine mount layout in my 32? It came with a 4 banger but these mounts were not being used. I'm told the car had a Y-block in it in 1961 but later had a 289 and a 283. 283 would have opposing mounts so that ain't it. I'm getting ready to cut them out and thought I'd document what we had before removing them.
Your help will help in figuring out the likely last engine used before the change to the 4 banger.
Thanks,
Al

 

Never had or worked on a Y Block but it appears it's staggered. (Sorry could not find same engine with both sides)

 

They could have used adapters that bolt to front of a number of engines that would have used the same stock flathead mounts. That is likely way would have done 283 and leave no evidence.

 

They appear to be Hurst frame mounts. These were used with most Hurst motor mounts, along with Ford motor mount biscuits.

 

I would say those frame mounts were for the 289..The mount holes on engine block are off set so if you use symmetrical block brackets the frame brackets will end up off set.

 

could have been any engine that they made off set motor mounts to clear the exhaust. moving that side back would allow a right side/rear outlet manifold to be used.

 

Thanks, fellas, for the insight and help.