Early 273 intake problems

All 64 to 67 273's, 2 barrel or 4 barrel, had forged cranks, forged rods, solid cams, and cast pistons. Even 2 barrel engines had 8.8 :1 compression and pistons .02" from the top of block. They respond very well to 4 barrel intakes and carbs, even if you do nothing else. Wiggle that intake and see if you can't get everything to line up. And do not use those sorry steel shim intake gaskets.