I think that my spark plug gap is supposed to be .045

My friend swears that it should be .035

I have small block chevys.
260 horse stock setups with normally aspirated quadra jet carbs.
5.7 liter GM 350 blocks.

My shop book says jack about plug gap.
(I looked all weekend.)
What should it be?

I want to change em tonight and splash the boat later this week.

Thanks!!

HEI should be .045
Standard Ignition .035


I would set them at .040 and call it good


BTW this is all a guess I have no documentation to back it up so set at your own risk

Thanks Scott.

The reason that I was thinking .045 was because that is the gap for my SBC in my GMC with HEI.
The boat has standard.

Now you and my friend BOTH say .035

.035 is in the lead.

Totally understand about the "educated guess."

Thanks again.

BTW Scott....

The truck is taken care of, the boat will be "done" (like a boat is ever done.) tonight...
Next project is that PC. So you will be getting thanked again soon.
I will be looking for chances to buy you guys drinks very soon, too.

Have a good one.