Spark plug debate: CR43TS 44s or 45s in 1989 350

[beachsuburban]

I have the 350 5.7 tbi mostly factory, there is info on here pertaining to the 305 and 350 crate engines but not much on the stock 350. Wondering what is the current conclusion on what plugs to run.
Thanks!

 

[Ricko1966]

Run the CR43TS unless you are having a problem fouling plugs. Even then you should find out why your are fouling plugs and fix it instead of trying to put a bandaid 9n it. Contrary to popular belief a hotter plug doesn't make more power,and could potentially make less as well as increasing the chance of preignition. You should run the coldest plug you can get away with and not foul. A cooler combustion chamber has a denser charge. Honestly though you are not going to make any appreciable difference by playing with spark plugs.

 

[Jawzjeep]

I run what Ricko1966 suggested. I ran 45s in a couple of cylinders that were getting oil soaked when I first started driving it. After driving it for maybe 500 miles I went back to the 43s. No issues

Edit: this is on a bone stock 91 Suburban TBI 350

 

[fast 99]

Do not spend extra money on any exotic plug. They will do nothing for a 350 other than drain the wallet. Buy plain old stock plugs.

 

[Turbo4whl]

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@Ricko1966 has posted good info on spark plugs. This chart shows the major difference between a hot and cold plug.

The "R" means it is a resistor plug, as most are now. The resistor is to combat FM radio interference. You may have experienced an older vehicle pulling up at a stop light next to you, and you can hear a click as each plug is firing.

One more interesting item. The high voltage current moves on the out side of the resistor. The current flows even better on a sharp edge resistor. Champion spark plugs have a saw tooth finish on the resistor. Problem is, through use, the saw tooth smooths out shortly. This is why a set of Champion plugs will fire any engine better when first installed.

 

[beachsuburban]

Awesome, 43s it is. Thanks for all the information!