Autolite 104 vs. AP104

The recommended plug for the SBF High Output engine (GT-40 heads) is the Autolite 764. It is my understanding that the 764 is being replaced by the 104. The basic difference is that the 764 has 1/2 threads and the 104 has full threads.

Assuming that the Autolite 104 is the "new" recommended plug, I noticed in the Autolite plug chart that the Copper Core 104, the Platinum AP104, the Double Platinum APP104 and the Iridium XP104 are all the same size, threads, reach, projection, heat range, etc.

The local price for the Copper Core 104 and the Platinum AP104 is the same. Any reason to stay with the Copper Core in favor of the Platinum? Background: I'm running an H.E.I. system (DUI) which many say works well with the platinum plugs.

JQ

It's not my intent to start a spark plug war...there are plenty of threads here and other similar sites where debates seem to roll on into perpetuity...

KENO: I think you've answered my question that the platinum plug will work fine with the HEI system. Since the cost is nearly identical, I'll give the platinum plugs a try.

This will make some people crazy, but I change my plugs out every year or two -- not because they need changing, but because I like tinkering. The same goes for the raw-water impeller, trans fluid, fuel/water filter/separator, red tail-light oil, rotate the air in the trailer tires, PCV valve, etc. The OCD voices in my head are telling me to re-torque the intake manifold bolts...again.

JQ

KENO wrote: Jonny Quest wrote: It's not my intent to start a spark plug war...there are plenty of threads here and other similar sites where debates seem to roll on into perpetuity... KENO: I think you've answered my question that the platinum plug will work fine with the HEI system. Since the cost is nearly identical, I'll give the platinum plugs a try. This will make some people crazy, but I change my plugs out every year or two -- not because they need changing, but because I like tinkering. The same goes for the raw-water impeller, trans fluid, fuel/water filter/separator, red tail-light oil, rotate the air in the trailer tires, PCV valve, etc. The OCD voices in my head are telling me to re-torque the intake manifold bolts...again. JQ Just curious JQ, is that red taillight oil synthetic and how much zinc and phosphorus does it have in it?

How fortuitous that you should ask...the ONLY BRAND that goes in my red tail-lights is Red Line.


JQ