I have been running the NGK R5674-8 in my 66 Skylark with the all iron 464. These are non resistor plugs and I'm trying to cross them to a resistor plug but I'm not having any luck. I'm just looking for a good resistor street plug for the car. Any help would be appreciated.
You're welcome Alan. It isn't an exact cross over to the plug you were running, but it is a resistor plug and works well in a lot of applications. The closest cross over to an AC plug is an R43TS. The plug you were running has an 8 heat range in NGK (higher number is cooler). Not sure why you would need that cool of a plug in an all iron 464. Try the UR-5 and see how it works for you. I run the equivalent plug with flat seat and gasket (FR-5) in my GS.
Tried to transfer a photo from my phone of an NGK UR-5 I've been running in my 464 for thousands of miles. Don't think the pic came through. Chocolate brown and nice and dry. Was going to get new plugs today but the NAPA guy handed me AC R45. I'm thinking that's too hot at 11:1 compression. Larry? I have 42s on hand but might spring for the 43s or just keep what's in it. Only pulled the #1 plug and will check the rest tomorrow. Ordered complete Holley Sniper and Tanks kit this afternoon. Let the games begin. Any change to plugs needed do you suppose? Told timing on MSD should remain the same. I'll take this to the appropriate thread (New Tech/Old Iron). Was just looking for spark plug info.
Id leave the ngkur5. Pulling one and. Heck for wear iseasy tho. They are real nice quality. You can experiment w the 42s at the track
(Hope this isnt is a hijack, but its related) Larry, I too am using fr5's currently. I'm try to find the 1 step colder equivalent and am running in circles with no luck. There isn't an "fr6", so I'm hoping the Wizard might know the equivalent??
Unfortunately no, there is a UR-6 but no FR-6. You can always go to the BP 6ES https://www.ngk.com/product.aspx?zpid=9405 That is the plug that TA lists in their catalog, page 131. Comes in heat ranges from 4 (Hot) to 9 (Cold)
Ok, thanks Larry, didn't think about checking the TA catalog. But then, that's why youre the wizard I suppose...
