What is the spark plug gap on a 305 Chevy engine?
A reduced 3.0-inch stroke was seen in the 1990s. The 305 had a lighter crankshaft than the 350 to balance the engine but was otherwise identical. The first models, LG3 and LG4, had some quality issues that tended to lead to premature wear on camshaft lobes, a problem which was fixed with the introduction of the 1982 LU5 model.
All 305 engines throughout the years share bore and stroke specs of 3.736 × 3.48 inches. Beyond that, there are a handful of variants that feature different horsepower, torque, and even fuel management.
Spark Plug Gap – understanding the basics. Spark plug gap is where spark plug spark discharge is designed to take place. On a conventional spark plug, it is the area between the center and the ground electrode.
As America faced an energy crisis and the government began to regulate a car’s emissions, General Motors made adjustments to many of their small block, V8 engines. GM introduced the Chevrolet 305 engine in 1976 to provide a smooth driving performance while allowing for lower octane fuels and lower emissions.
Use the distributor adjusting tool or the proper size Allen wrench to make the adjustment on the newer model Chevy distributor. Most gap points for Chevy small-block engines require . 016 to . 019 of an inch.
In general, the high compression 283 (with a good “street” cam, heads and headers) likes a lot of initial timing…… somewhere around 12 degress btdc, and full-in timing around 38. They also like full advance by around 2200 RPM….you will need to re-curve the distributor from stock.
Plug gap goes with combustion chamber and engine design NOT the ignition system. A 327 needs . 035 not the . 045, the 045 just askes for increased energy thats not needed with the combustion design.
For most racing applications, you usually want the plug gap to be between 0.020 and 0.040 of an inch. Most engine builders seem to settle around 0.035 of an inch. Factors such as the type of ignition you run, cylinder heads, fuel and even timing can affect how much gap will work best for you.
45 gap, AC R45TS plugs.