TBI spark plug gap

[89 jimmy]

Stock TBI 5.7 calls for .35 spark plug gap. Is there any benefits to gapping at .40 or so for possible better fuel burn, less hydrocarbons at smog, mpg? Or will that put more strain on the ignition components? Any feedback from people who have done this?

 

[dyeager535]

Stock TBI 5.7 calls for .35 spark plug gap. Is there any benefits to gapping at .40 or so for possible better fuel burn, less hydrocarbons at smog, mpg? Or will that put more strain on the ignition components? Any feedback from people who have done this?

HEI never really changed. Even the computer controlled stuff operates the same way, essentially.

GM ran from .035 to .080" on the HEI setups. You can run whatever you like. I generally like to set them at the low end, so as they erode I don't end up with a ridiculous gap.

I've run .035-.050 on my setup and noticed no difference in how it ran, or MPG, which I always measure.