A worthwhile read for C3 newbies. Here’s an easy upgrade.
Over the past 49 years of my car enthusiast life, things have changed. We had local mechanic shops with hot rods, race cars, and muscle cars sitting out back. There were manuals that broke everything down with photos so you could actually get through a repair or upgrade. And the monthly car magazines—I still have plastic bins full of them. I even made binders for different projects.
Those days are long gone…
For those a couple generations behind on the car scene, here’s a blast-from-the-past upgrade if you’re getting into an early C3.
I’m 65 now, and this has always been fun for me. It’s my hobby. I don’t have the same ambition I once had, but I still like to stay active.
I’ve had a 1968 327 L79 for about 3 years. I settled into a “stock-ish” look. After doing a few body-on restoration jobs over the years, I’ve found refurbishing is the sweet spot if you know what you’re doing.
I started getting a little bored with the performance on the 68 Vette, It ran fine… it just felt like something was missing.
So I went down the rabbit hole on these 327s.
What I couldn’t understand was how the 1968 L79—with a cast iron intake and Quadrajet—was rated the same 350 hp as the 1965–67 L79 with an aluminum intake and a Holley.
Didn’t make sense to me.
So I tried it myself.
My goal was to keep it stock appearing:
- Had to fit under the hood
- Needed the oil fill tube
- Had to make sense money-wise
I passed on the Edelbrock 2703—price just didn’t sit right with me. Found a vintage Edelbrock C3BX for $175 instead. I already had a Holley 1850 that needed a rebuild, so I went with that.
After the swap and a few hours of tuning over a couple days…
Big difference.
The torque increase is noticeable right away. But more than that, the car just feels more alert to your foot. Throttle response is there now. It finally feels like what I expected.
My take?
GM may have been a little generous with that 1968 rating. Maybe it hits 350 hp on a dyno—but on the street, I don’t see it matching the earlier L79 setup.
If you’ve got a 1968–72 small block with a Q-jet and cast iron intake, you might want to rethink it.
You’re leaving something on the table.
The Holley 1850 tune-
* #70 jets
* Secondary plate- #134-21
* Brown secondary spring
* 10.5 Power Valve (the 327 pulls 21” of vacuum at idle
* Pump Cam- Red #2 hole (20cc)
* #31 Accelerator pump nozzle
Timing-
* 17° initial
* Total timing- 36°@ 2700 RPM
* Idle timing total (initial plus 11° of vacuum advance) Idles at 930 RPM.
Anyone else run both setups and see the same thing?