Chrysler engineers in the fifties were good at spending extra money to obtain little if any real benefit. Canted valve poly heads that didn't flow as well as cheap wedge heads (at least the poly heads were cheaper than hemi heads, albeit not nearly as effective), ball and trunnion u-joints that were a bear to service and weren't any smoother (to my insensitive butt) than normal u-joints, dual leading shoe drum brakes that also were a bear to service and, even when adjusted correctly, of questionable benefit in the real world, and (late forties and early fifties) fluid drive transmissions that were more complicated than a real automatic transmission and killed performance - just so Chrysler products could keep their "safety clutch."
I say this as someone who owns several of these cars and loves them all despite their quirks.
My 56 Belvedere, with a 277 poly, factory four barrel and dual exhaust (not original carb or air cleaner). Motor looks just like a 318 poly.
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