If there is an issue, it will be in the size of the exhaust port on the manifold versus the block. It should be an easy comparison to make, almost visual in nature, but certainly easy enough to measure up.
I honestly don't know if they are compatible, since there has been so many head changes in EFI 5.7l
I take it you found some salvage late model manifolds, because the old style CC manifolds are still commonly available.
1964 36'Challenger 'Vanora'
1965 21'Supersport 'Mary Elizabeth'
1946 18' Atkin ketch 'Dove'
1952 14' Peterborough 'Ruby'
1922 8' Gregory 'Miz Samson'
Large piles of wood, tools, motors and other very very valuable stuff