Ideal Ignition

[jacob_coulter]

What is an ideal spark plug gap for a standard chevy 350 with stock Hei, stock coil? I have a 78 k5 Blazer with 350. Is .060 too big of a gap?

Thanks

 

[78Suburban]

Haynes Manual says .045 for that year for a bone stock truck. I just gapped and installed mine recently.

 

[dyeager535]

.060 is pretty large, you'll typically see .035 or .045, HEI will easily "jump" any of those in normal engines though.

Typical advice on plugs is to increase the gap until you see no increase in performance.

Except under extreme circumstances, plug gaps from .035 to .060 are not going to make much difference, if any, to you.