# What is this? (1975 455 with 51-6 heads)



## Gravity1972 (Oct 16, 2021)

I inherited this engine some time ago with the thought of swapping out the 326 in my '66 Lemans. 

Recently pulled the engine ( 1975 455 originally from a grand prix?) out of storage and noticed that there are open areas on the top center of each head where the intake manifold meets. What are they and are they normally blocked off?

Any input is appreciated!


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