1.6 rockers

It DEFININITELY wasn't a Mopar, but I had a 63 VW with a 1200 cc 40 HP engine that had a set of big bore cylinders that took it up to 1385 cc, a mechanical advance distributor, & a header. It came stock with 1 to 1 rocker arms. Later models had 1.1 to 1 rockers. I bolted on a set of the 1.1 to 1 rocker arms (giving a theoretical 10% increase in lift) & you could feel the improvement in performance.