In the later decade of 1970s and early 1980s, if you were into “daily-driver” cars that offered performance, there was a special allure about American V8-powered “Muscle Cars.” While in high school, this 1970 Plymouth Road Runner was my first car. It was a nice start, too – except like most guys in my San Fernando Valley neighborhood as well as school auto shop class, we always wanted to do MORE.
In this case, I took the stock 383-cubic-inch motor out and went shopping for everything I could afford to give it a boost – and if you’re a bit technical and know the vocabulary of the hobby, this will give you an idea of where my “pocket money” went: From the standard cylinder bore I had the block bored an additional .060 and fitted with new TRW forged pistons and chrome-molly rings, had the block align-bored and decked, installed an Iskenderian racing cam and fresh valve train — springs and aluminum retainers, had the cylinder heads ported and polished, had the crankshaft turned .010/.010 and then re-hardened (tuftrided) before fitting Clevite 77 rod and main bearings, along with having the connecting rods rebuilt (re-machined big ends) and shot-peened for surface hardness — and then finally de-burred the entire block. When it came to taking a zillion RPM grinder to remove every single casting burr on that block, by the way, that took a couple of hours and had me wondering, “Why am I doing this again?” about every fifteen minutes (the vibration of a zillion-RPM grinder is not a lot of fun, but the reduced block fracture-point from casting burrs is the worthwhile outcome, of course).
For a more free-flowing exhaust I installed a set of Hedman headers and Chrysler Hemi mufflers, while on the induction side I used a Holley 780 c.f.m. carburetor with mechanical secondaries. Wanting more standing-start quickness, I replaced the factory stock 3.23:1 rear axle gears with a set of 4.56:1 gears and modified the rear suspension with a pinion snubber (over the center of the differential) to force the rear end down on the tires and minimize wheelspin under launch acceleration.
It all worked as planned, except after spending all of this money on the Plymouth, I remember hardly having enough money to put gas in it. Plus – just after buying this Road Runner, I also bought a 1970 Chevrolet Chevelle SS396 — which was destined for its own share of hop-up tweaks. At the time, the fact that I was able to own and drive either one of these fun Muscle Car-era cars meant times were good.
If I encountered another muscle car that might be stronger than the SS396 Chevelle, I could always say, “Wait right here and let me go grab this car’s ‘brother’ “… and return with the Mopar’s 12.7 to 1 compression advantage and the surprise it delivered from an otherwise fairly stock-looking Road Runner.