spark plug for 1985 K30 454 4 speed??

DonSSDD · Canadian Poncho Superstar!

spark plug for 1985 K30 454 4 speed??

73SC · A Poncho Legend!

My 454 is an '83 from a K30 4 speed. I have used the R44T AC Delco plug as recommended by GM. I was luck enough to find several NOS boxes at a swap years ago and have never had to look for plugs for the 454, although what seemed like an unlimited supply is now dwindling.

I had NGK in it for part of a season a few years ago but pulled them out part way through in favour of the AC Delco's.

OURWAGON · Guru

73SC wrote:
My 454 is an '83 from a K30 4 speed. I have used the R44T AC Delco plug as recommended by GM. I was luck enough to find several NOS boxes at a swap years ago and have never had to look for plugs for the 454, although what seemed like an unlimited supply is now dwindling.
I had NGK in it for part of a season a few years ago but pulled them out part way through in favour of the AC Delco's.

I USE DELCO BUT PUT NGK IN MY 5.3 , THEY WORK FINE.

I WORKED AT CARQUEST FOR 14 YEARS AND WE WHERE TOLD

NGK MAKES PLUGS FOR AC DELCO !!

73SC · A Poncho Legend!

OURWAGON wrote:
73SC wrote:
My 454 is an '83 from a K30 4 speed. I have used the R44T AC Delco plug as recommended by GM. I was luck enough to find several NOS boxes at a swap years ago and have never had to look for plugs for the 454, although what seemed like an unlimited supply is now dwindling.
I had NGK in it for part of a season a few years ago but pulled them out part way through in favour of the AC Delco's.
I USE DELCO BUT PUT NGK IN MY 5.3 , THEY WORK FINE.
I WORKED AT CARQUEST FOR 14 YEARS AND WE WHERE TOLD
NGK MAKES PLUGS FOR AC DELCO !!

Oh, they worked fine I just couldn't stand seeing them in there.

DonSSDD · Canadian Poncho Superstar!

I found out Id have to wait a week for NGK, went with delco, they were in stock. Thanks, Don

4SPEED427 · A Poncho Legend!

Our experience at work with NGK was good but I'm still convinced from what I've seen over the years is nothing works better in a GM than a Delco plug. It may well be that NGK makes them but that doesn't necessarily mean they are made to the same spec as an NGK plug. If I couldn't buy Delco it would certainly be NGK.

Prefectca · Poncho Master!

On the question about iridium. I replaced the exhaust manifolds on my 2015 6.0 due to broken manifold bolts. I bought new manifolds because the parts were reasonably priced, and I changed the manifolds at home and didnt want any problems. The truck has 220K and I pulled the original spark plugs and they still looked fine. I replaced them with AC platinum plugs because I had a set from my previous truck that I never used. Its really interesting that the plugs lasted so well. I wonder how long they would have lasted if I hadnt changed them.

Paul

DonSSDD · Canadian Poncho Superstar!

Biggest risk is they may seize.

Our other fire truck is a 2007 GMC 8.1L, it developed a bad miss with about 3,000 kms, but about 5-6 years old and likely some more hours than kms. Had a gm program hooked up to it but it didnt show anything. An acquaintance who was a gm tech said check the spark plugs. Turns out the tip was gone off 1 plug, another 2 were partly missing. They looked like they were burning off as opposed to breaking off, new plugs and it worked like a charm, still does. Factory ACDelco platinum, not sure what could have caused them to do that.

DonSSDD · Canadian Poncho Superstar!

So I got a new set of ac delcos, the old plugs were 7 autolite and one ac delco, an R42, whats that?

Truck has 7100 kms, not sure how many hours. Not sure when or who did plugs before, I only got involved recently in maintenance. Not sure why 1 plug is different unless that was all anyone could find at the time?

Truck is not driven much, averaged 200 kms a year for 35 years. Carb is. Quadrajet, hasnt been touched in my time amd the last guy who touched the carb has been dead since 2007. I got the department to start using premium only, ethanol free, when I joined about 2008. I dump some sea foam in it once a year. It doesnt get 200 kms on a tank, small tank and big appetite for gas with the 454.

What really impressed me is the condition of the old plugs, I thought youd appreciate seeing them and I thought they were pretty clean given age and use.

-- Edited by DonSSDD on Thursday 10th of December 2020 04:03:38 PM

Canadian Poncho · A Poncho Legend!

I think we need to see a photo of this truck.

DonSSDD · Canadian Poncho Superstar!

It's still in my yard

DonSSDD · Canadian Poncho Superstar!

Can you fix the orientation Todd? Its a 3 pedal truck of course, a 4 speed with a granny low.

4SPEED427 · A Poncho Legend!

DonSSDD wrote:
So I got a new set of ac delcos, the old plugs were 7 autolite and one ac delco, an R42, whats that?

Truck has 7100 kms, not sure how many hours. Not sure when or who did plugs before, I only got involved recently in maintenance. Not sure why 1 plug is different unless that was all anyone could find at the time?
Truck is not driven much, averaged 200 kms a year for 35 years. Carb is. Quadrajet, hasnt been touched in my time amd the last guy who touched the carb has been dead since 2007. I got the department to start using premium only, ethanol free, when I joined about 2008. I dump some sea foam in it once a year. It doesnt get 200 kms on a tank, small tank and big appetite for gas with the 454.
What really impressed me is the condition of the old plugs, I thought youd appreciate seeing them and I thought they were pretty clean given age and use.

-- Edited by DonSSDD on Thursday 10th of December 2020 04:03:38 PM

Those plugs look new!

I"m betting they were chasing a miss on that cylinder, or else broke one installing new ones and had to use an old one over again, or buy one somewhere else.

Canadian Poncho · A Poncho Legend!

Images fixed.