Spark plugs... woo hoo

[justice]

Well i have just completed one of the rights of passage for an astro/safari owner...i changed the spark plugs and wires. yay for me. I was going to replace the EGR valve and install a screened gasket but after sizing up the job, i decided to leave that one to the pros.

anyway, the plugs that came out of the van (1992 - Z motor) didn;t look to bad, a little carbon but mostly the light brown color. No oil fouling.

Now my questions for you spake plug gurus..

The plugs I installed were AC Delco CR43TS gapped to 0.045 per my factory service manual.

The plugs that i took out were Bosch Super R6 10 291 and the ones I checked were gapped approx 0.040.

Your thoughts about this difference in the plugs?

[Smiliesafari]

.005 of an inch doesn't make a bit of difference.

[justice]

couple of things...

the plugs i removed from the engine are actually BOSCH HR10BC. From all of the cross reference charts I can find, this is not a plug that crosses with the AC Delco CR43TS.

Another thing that concerns me. Everything I am finding online says the gap for my engine should be 0.035 but my factory service manual says 0.045 which is what i gapped the plugs at. :-k Why the descrepancy???

[Smiliesafari]

Well, we know the Bosch plugs aren't OEM. I'd go with what the FSM says and gap the AC's at .045. The larger gap will generate a bigger spark. Some of the electronic ignitions will generate enough energy to produce a spark that will jump a .060 gap.