1968 PLYMOUTH ROAD RUNNER

ENGINE

Two potent V-8 engines were available in the Road Runner for ’68: the standard, 335-hp 383-cu.in. B-series big-block, which used heads, cam, and exhaust manifolds from the Super Commando 440, and the legendary 425-hp, 426-cu.in. Hemi. Off-the-shelf parts for both are still readily available and original parts for 383 cars remain plentiful. Finding correct, vintage Hemi parts is increasingly difficult and expensive, but not impossible. Both engines offer myriad upgrade possibilities to the owner who is interested in the Day Two or restomod treatment.

TRANSMISSION & AXLES

Buyers of new Road Runners in 1968 had the choice of the standard A833 four-speed manual transmission, with Inland (later, Hurst) floor shifter. Optional was a column-shifted TorqueFlite A727 three-speed automatic. Both are famously robust and remain well supported. Standard was a 3.23:1-geared 8¾-inch axle. A 3.91 Sure Grip was the