Autolite 24 or 25?

[Boomyal]

I'm getting my new stroked 302 (now 331 cid) ready for the boat. I'm running an appropriate cam w/ comp promagnum roller rockers, a 4 bbl holley with Edelbrock performer manifold and a stock mechanical advance distributor with a Pertronix II and Flame thrower coil.<br /><br />I'm not sure what all the differences are between the 24's and 25's except for the wider gap on the 25's.<br /><br />Any recommendations?

 

[snapperbait]

Re: Autolite 24 or 25?

Heat range... I run the 25's in a 302 roller cam motor with no problem.. 25's are the recomended plug in the ford 302 HO motors..<br /><br /> Other good plug for that would be Motorcraft # ASF42C, gapped @ 0.050" ..<br /><br />You may want to check with Pertronix as some aftermarket ignitions recomend different plug gaps...

 

[ron7000]

Re: Autolite 24 or 25?

the autolite 24, 25, 26 have a 0.460" reach with projected tip (which is common) and 14mm threads.<br />the difference between them is heat range. For American plugs, the higher the number for the same model plug means hotter plug; lower number is colder. It's the opposite for Jap plugs, higher nuumbers are colder (NGK TR6 is colder than TR55, TR5 is hottest of the three).<br /><br />download the 2Mb excel matrix for a full cross reference of all plugs http://ngkaz.home.att.net/wsb/html/view.cgi-home.html-.html