What is the spark plug gap for a 1971 Chevrolet 454?

Answer 1

.035 is recommended.

This much is true, but a greater truth is the spark is fired based on the spark plug gap. I have found a simple process that works with all single coil systems that can generate more power and MUCH better combustion efficiency.

It works like this:

1) Take your stock plug and increase the gap by 20%. (.040 +.008=.048) and reinstall it into your engine.

2) Check for misfire on that cylinder. If no misfire, increase the gap by an additional 20% and reinstall, repeating the check for misfire.

3) Once you reach the point the plug fails to fire, go to the previous setting.

4) Apply this setting to all plugs.

5) Road test. If you mileage is DOWN, then regap, narrowing it by 10%.

I have found mileage gains as much as 5 mpg's using this process!

Try it!