Spark Plug Screwup Will it hurt?

[64drtGt]

I got a set of plugs for my 98 Durango 318 and a set for my 93 truck 318.

I wasn't really paying attention to the fact the plugs were actually different I put the rc12yc's in the Durango. Will having the shorter nosed plug in the newer motor hurt ? I don't have emmisions where I live.

 

[daredevil]

Shouldnt hurt a thing other than adding a few cc,s to your combustion chamber.

 

[UOP]

Even though they're the same engine, the early magnums spec'd a hotter plug (2 steps hotter). I don't know if that will cause a problem but why not just switch them out?

 

[64drtGt]

They are both the same heat range just different length

 

[fishy68]

I'd make it right. By using a shorter plug it'll let carbon build up in the lower threads possibly making it difficult to put the right plugs in next time. Plus they probably won't burn as efficient.

 

[UOP]

They are both the same heat range just different length

Gotcha, I had to look that up and you are correct. I was basing my info on experience with NGK plugs (my preference) and they list the FR4 plug for your P/U and the ZFR6F-11 plug for the Durango, which is a colder plug.