Engine change/compatibility

I have a 1984 Caddy coup de ville. The 4100 engine is on its way. I want to know what is compatible as a drop in.

4500?, Northstar? 350ci of some sort???

Thanks in advance

I’m guessing the 4500 and 4900 will swap, it’s the same block. You might call a parts recycler (AKA junkyard), they have interchange catalogs that might help. I doubt the Northstar would be a drop-in.

I believe that the 350 was an optional engine that year, or years close to it with the same body style. The 4100 wasn’t a good seller so Caddy began to offer the Chevy engine as a more powerful option.