[dpoltzer]

My local NAPA does not carry AC Delco plugs for my 1970 T/A RA3. They show Autolites as a substitute. Any one here have experience or opinion on these Platinum plugs? Thx.

[Formulajones]

I use Autolite in everything here, but not the platinums. I prefer the standard copper core,... Autolite is an excellent plug.

I dumped AC a long time ago when they started deleting various heat ranges and monkeying around with their number system.

[prostreet64]

Ditto what Formulajones said. We use the standard Autolite copper plug in both my 403 olds and in Curtis's 400 poncho. Heat range 85; they have given excellent service.

[Mook]

Add me to the list of those who use Autolite’s copper plugs... 💪🏾

[77 TRASHCAN]

Originally Posted by Mook

Add me to the list of those who use Autolite’s copper plugs... 💪🏾

Same, here.
No need to spend the $$$ on platinum...ever...

[steve25]

I have never had a Autolite plug let me down.

[shaker455]

Originally Posted by dpoltzer

My local NAPA does not carry AC Delco plugs for my 1970 T/A RA3. They show Autolites as a substitute. Any one here have experience or opinion on these Platinum plugs? Thx.

Autolite plugs work great!
Do not use platinum plugs in a carbureted engine.
They are intended for FI engines with constant precise metering.
I had many customers cars here with platinum plugs and engine not running right because of it.
Stick to copper core

[4dblnkldude]

I use autolites in everything except my 69 which I use NGK's. I've hear about the platinum plugs in carbureted cars but never quite understood. Can you tell me more about it?

[dpoltzer]

Thanks for all of the great input! Autolite copper it is then!!

[lust4speed]

Yep. Changed over to Autolite after Champion went down hill followed by Delco a few years later.

[dhcarguy]

What # Autolite plug replaces the AC Delco R44S plug. (copper). Also the NGK equal.

Thanks

[Formulajones]

Originally Posted by dhcarguy

What # Autolite plug replaces the AC Delco R44S plug. (copper). Also the NGK equal.

Thanks

That would either be an XR4 in NGK or an Autolite 85

[Formulajones]

NGK is a great plug too. Just have to remember the heat ranges on those work backwards from our traditional way of thinking.

For a colder plug the number goes up, not down.

[lust4speed]

This is probably a discussion for another time, but with my engine set up with lower compression than stock (9.3:1) and spending more time leisurely cruising than hauling the mail, I usually run Autolite 86 plugs which is equal to the AC R45S plug. The overdrive trans also keeps the freeway trips down to a rather mundane range in the low 2,000's.

[Formulajones]

Originally Posted by lust4speed

This is probably a discussion for another time, but with my engine set up with lower compression than stock (9.3:1) and spending more time leisurely cruising than hauling the mail, I usually run Autolite 86 plugs which is equal to the AC R45S plug. The overdrive trans also keeps the freeway trips down to a rather mundane range in the low 2,000's.

Yep all good points. I bump the heat range up on our drivers too. Another reason being up here at 5,000 feet and then driving either higher up, or down to sea level, I tend to keep the carb tune a little on the rich side of things so the engine is in a decent range at sea level, and the warmer plugs still look pretty nice with a bunch of idle and low rpm cruising up here.