I have a 84 ford f150 with a 87 4.9l 300 FI engine that was converted to carb with the 84 parts. I went to oriely and bought autolite 5125 plugs because they didnt have motorcraft plugs. I was told by the guy that he doesnt think autolites are that great and that he trys not to sell them but anyway I bought them. I read the reviews online and some people say they suck others say they are okay. I retured them to oriely and bought champion spark plugs from fleet farm part number rf14lc copper plugs, they arnt even the champion truck plugs. As I returned autolite the plugs the girl told me that champions are not that great for trucks and she doesnt reccomend them, she said they are mostly made for recreational vehicles. She said that I should put autolites or motorcraft plugs In my truck. Im not sure If I should keep these champion plugs or If I should return these champions and buy autolites again. Which one would be better champion or autolites. I cant find motorcraft In a couple stores around me, are autolites Just as good as motorcraft and should I put them In my ford or should I put the champions In though. I have read other threads about a one piece or two piece plugs. Has anyone used the autolite 5125 plugs, how did they work.

 

of those two choices, I'd run the champions



but in reality I wouldn't run either of 'em willingly

 

The 4.9 I-6 will run fine with standard Autolite copper plugs.

 

Autolite, and Motorcraft are both made by an Allied Signal company called Honeywell. I have heard that some of the specifications are tighter on the
Motorcraft, but I would sure use an Autolite over a Champion anytime!

 

^^^Absolutely correct. I prefer Autolite over Motorcraft due to the price. I have Autolite plugs in my '68 Ranchero (289 ci) and '94 L.

On a side note; I had a '74 LTD with a 351W that would foul Motorcraft, Autolite and Champion plug's. I installed a set of AC Delco plug's and never had anymore fouling concerns.

 

I think people overthink spark plugs specially on standard engines. Your standard copper top single prong plug will be fine and actually work better. I have a performance boat with twin 454 big blocks and all thats reccommened is the standard plug.

 

I've ran autolites in several vehicles including my mach i for years and never had a single issue. Years ago I ran champions in my dads old chevy truck and they didnt make it a year. I would be reluctant to run them in my lawnmower.. Autolite years ago was ford part brand name. My Mach i came with autolite plugs. They are manufactured on the same production lines as Motorcraft plugs. Some have had issues running them in Modular engines but in old engines I really think there equal to Motocraft..

 

AC makes a good plug. I've used them in lots of cars.

 

Autolites over champions all day long for me.