Spark plugs 1974 \ 454 HEI?
 

I searched before posting and found several plug threads but didn't find one with my exact setup: Stock 74 low compression 454, with HEI and headers.

The book says a 454 in 74 should have AC Delco R44T plugs, but that was back when points were used and it currently has a later model GM HEI dist.

Would the R44T still be the recommended plug or should I go with the R44TS that GM started using after they went to the HEI?

And would there be any benefit in upgrading to platinum on this old motor other than longer lasting or maybe less prone to fouling?

The truck is mostly used for short trips right now. No plans to do any work or take trips with it. It runs good and doesn't smoke but uses roughly a quart to maybe a quart and a half of oil every 1,000 miles. I'm assuming that not unusual for a 454 with 106K. I had a 73 \ 454 with 78K and it used the same amount if I remember right.

Thanks!

Re: Spark plugs 1974 \ 454 HEI?
 

R=resistor
44=heat range
T=tapered seat
S=extended tip
X=wide gap

As long as the extended tip will not interfere, sure go for it, but you'll still have to widen the gap to at least .045

Re: Spark plugs 1974 \ 454 HEI?
 

I'm not sure about the extended tip though.

Re: Spark plugs 1974 \ 454 HEI?
 

I use the R44T and gap it 0.045”.

If your burning oil, you may want to use a R45T plug, which is 1 heat range hotter. Might help with fouling of plugs. Still gap it 0.045.

As far as the extended tip, make sure it will not contact the pistons or you could create bigger issues.

Re: Spark plugs 1974 \ 454 HEI?
 

Use the extended tip plugs. They are a big improvement over the old style recessed tip plugs. They are used in o-head valve engines only & will clear in all the normal o-head valve engines. Set the gap at .045. If they are tapered seats use R44ts or R45ts. Older engines used a flat seat with a gasket. R44S or R45S.
George

Re: Spark plugs 1974 \ 454 HEI?
 

Well crap. I just received a set of R45T plugs that I ordered a few days go. I appreciate the note. It's exactly what I was looking for.

I'm waiting on the cap, rotor and wires to arrive and in no hurry so I'll see if I can exchange the plugs.

Many thanks.

Re: Spark plugs 1974 \ 454 HEI?
 

They will work just fine. Gap em to 0.045” and you’ll be fine.