64-5 intake bolt angle

I didn't measure exactly, but the bolts go in ~16 deg off vertical in 64 & 65 273 heads. That is a rare HiPo cast-iron manifold you have. I finally found a 4 bbl aluminum intake for my 65 Dart 273. Haven't installed and currently have a 66+ alum intake on it which was a bit tricky by counter-sinking the holes and using flat-head screws. I hope to eventually try fitting a Magnum beer-barrel intake to my 65 heads. It has vertical bolt holes.