Is there a hotter plug for my application that would be a better use?

272 y-block - just modified to a 1957 intake, 0-8007- 4160 Holley carb and a 8383 MSD HEI distrubtor, I know there's a lot of brands of plugs, when I bought the car, the seller said Champions only, anyone else experienced this?

With a basically stock Y-Block 272-312 I like the Autotite double Platinum APP 45 gaped .035.


-Gary Burnette-

I've been using Autolite 45's. Why do you want a HOTTER plug?

Which plugs are currently installed?
The stock plug would be an equivalent to an Autolite 46.  There is no reason that Champion only should be used.  Maybe the seller just likes champion.



Lawrenceville, GA

Well I think he had a purpose for keeping it stock as possible as most of them came with champions, but thanks I will try the autolites.

Autolite #45 works for most Y applications.  If the compression ratio is on the low side or the engine is pulling some oil past the rings, then Autolite #46’s.  I run the Autolite #46’s in my ’55 Customline with its 272 and original small valve heads.

Lorena, Texas (South of Waco)

Currently using Champion RF14Y but their very dirty which tells me the car has never been running right, one day I hope to have it running the way I know it can. Just found out the other day that the guy who sold it to me put a different type cam in and supposedly that could be effecting the idling, he set this car up for himself and when it sold he didn't offer any changes me made to the motor other than it was rebuilt, rebored to 292 specs and that was it.

I just put a set of NGK V Fire plugs in mine. It's too early to tell if they are in the right heat range. I plan on putting a few miles on them and I'll let you know how they look.

Durham Missouri

Put Autolites APP 45 in my car today, gapped at 35, won't fire a lick. At least with my old plugs it would start. Any causes?

I seem to recall MSD recommends not using platinum ?