Spark plugs

[Huckleberry]

Hey everyone, what's the best spark plug for a 350 crate motor. " bone stock" daily driver, please advise on plug gap. Thanks in advance

 

[Memaloose]

1978 Chev 350 factory gap is .035"

 

[DoubleDingo]

ACDELCO. Gap is .045 with HEI if I recall correctly, and .035 with points. Go to the local auto parts store, rock auto, or whatever, plug in your truck's info and get the ACDELCO plug for that application. Not the fancy iridium or platinum, just the plain-jane copper plugs.

 

[Bextreme04]

It will be an ACDelco R45TS. That was the specified plug for almost every small block(and some big block) GM engine for decades. My 71 Buick 455 uses the same plugs.

 

[Huckleberry]

Thanks everyone. Appreciate you all.

 

[geolee]

It will be an ACDelco R45TS. That was the specified plug for almost every small block(and some big block) GM engine for decades. My 71 Buick 455 uses the same plugs.

I was just reading this and have always thought cr43ts was stock plug and the 45 was just a hotter plug

 

[Bextreme04]

I was just reading this and have always thought cr43ts was stock plug and the 45 was just a hotter plug

the second number is the heat range. Higher number is hotter plug. A CR43TS, CR44TS, and CR45TS will all fit and work in most GM V-8 engines from the late 60's through the 90's. 43 will be a colder plug, this means it will dissipate heat away from the tip of the plug faster than a 44 or 45. If you have a low compression truck engine that is mostly stock, you will want the hotter plug to keep the engine running right. If you are running boost or a higher compression ratio, hotter cam, etc... then you might want to start looking at a colder plug to keep it from overheating.

 

[fast 99]

CR43, C indicates commercial, ground electrode is wider heavier duty. Primarily designed for 2 ton and larger trucks. Will work on light duty in a pinch.

 

[geolee]

CR43, C indicates commercial, ground electrode is wider heavier duty. Primarily designed for 2 ton and larger trucks. Will work on light duty in a pinch.

Well hell lol. Idk where I heard CR but just never questioned it. I think my 94 truck has R44t but pretty sure my 84 has CR43 I'll have to check. Thanks for the info guys!

 

[bucket]

I believe the CR/R43-45 variants were specified for various applications in the 70's and 80's. For the average stock engine in most driving conditions, I think any of them would be suitable. I like to run an .040 gap with HEI.

Just check the plugs after a good amount of use and see how they look.