Help with my first engine build (5.9 Magnum)

Well I got the oil pan cleaned up pretty well, just needs a good degreasing and I think I could throw some paint on it. However, am I wrong in thinking a late 1960s LA pan from a 273 will fit my Magnum? (The regular Magnum truck oil pan won’t fit my A-body). I thought I read that a modification to the gasket was all that is needed. I set the pan on my motor and there is quite the gap between the engine and the pan. Maybe my cleaning was for nothing…

*in the picture the pan is on backwards, I was doubting myself flipping it around checking both ends when I took the pictures.


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