Removing my 273 engine

If you didn't mark the hood position exactly, you may spend a lot of time trying to realign it perfectly (how would I know?). I don't think a Sharpie outline of the brackets is sufficient (wasn't for me). I suspect the factory aligned it with a worker inside the empty engine bay to tighten the bolts once perfectly aligned. You might consider doing that while your bay is empty. Once aligned, if you drill 2 small holes thru each bracket before unbolting again, you should be able to bolt it up perfectly, by inserting nails in the holes. My 1985 M-B designers were thoughtful. The hood brackets have release levers which allow it to be opened to the vertical for maintenance. Wish I knew that trick when I swapped an engine and first removed the hood, thinking necessary like when I did that in my 1969 Dart.