What brand spark plugs do you use for your 351C?

7173Mustangs.com

Help Support 7173Mustangs.com:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

4mm

Well-known member
Joined
Aug 26, 2012
Messages
447
Reaction score
3
Location
S. TX
My Car
1971 Mustang 351C 4V Fastback
I have a 351C 4V stock but with headers. I've always had success with AcDelco Rapid Fire spark plugs. From the seat of the pants feeling they provided a smoother idle and smoother acceleration (not necessarily faster lol).

Which one of these two would be best suited for the engine? I cannot grasp the differences.

https://www.summitracing.com/parts/ado-1

https://www.summitracing.com/parts/ado-2

I am also almost ready to to fire her up and is there any recommended oil filter for the 351C 4V? Thanks in advance.

 
I'm using plain ole Motorcraft ASF 42C copper plugs in my stock 351 4V seems to really like them, I tried more expensive platinum ones but ended up coming back to the copper Motorcraft plugs, the motor seems to like them better. As for oil filter I'm using a WIX 51515 oil filter. I'm sure there are numerous other plugs and oil filters that would work fine but that's what I'm using and happy with them.

 
Last edited by a moderator:
Autolite or Motorcraft... that's what came with the cars back in the day. I have some Autolites in my '71 right now. Fires right up, doesn't 'sputter or miss until it warms up,' or anything like that - even with a not-100% tuned 4bbl carb.

Don't waste your time with the Split-Fires, Bosch Iridium Tips, NGK Platinums, or XYZ Unobtainium Triple Core Snake Oil filled Super-Dupers - they're spark plugs... they spark until it's time to change them out for new ones. Non-exotic plugs work well, and last about as long as you'd really want them to last between tune-ups... and are cheap enough to simply replace every 3rd or 4th oil change (you're going to pull them every time you tune up the engine to make sure the gaps are right, anyway... right?) ;)

I've gone down that road in both my '97 Ram and '80 Jeep. I tried the Bosch Platinums in the Jeep (had a couple of cores delaminate, slide out and close the gap - killing the affected cylinders, of course). I tried Champion Truck plugs in the Ram, with no change in performance, but a minor drop in mpgs. I also tried Split-Fires in my '85 Nissan 4x4 (hoping they would resolve a misfiring issue I had - nope). The only noticeable difference with all of those different kinds of plugs, was how much lighter my wallet was each time I came back from the parts store with the latest snake-oil spark plugs.

Champions. Straight-up, old school, 'the ones recommended for the car' Champions, are what's in my Jeep... and it runs better than ever. Same with my '97 Ram... the new owner asked what plugs to use, I told him the history, and he said he'll get another set of Champions when it's time to replace the ones in there now.

Maybe it was all psychological, but it just seems like none of those 'too good to be true' money-grabber plugs really did anything except cost me more money.

WIX, Fram, Motorcraft [oil filter] - whatever you like. Some supposedly work better than others... most do not [work any better than others]. I gave up trying to spend more money on negligible return big name-brand things - like K&N. Love their air filters... oil filters, not so much. I like their air filters because I can clean and reuse them whenever I like, but the oil filters are just more expensive and don't do a whole lot differently than the others I mentioned above.

I won't even talk about motor oil. ;)

 
+1 on the champion plugs. I run them as well. No issues what so ever running in an untouched 351c 2V with the exception of headers and Pertronix ignition. The intake manifold have never even been off the car. For the oil filter I ran the Motorcraft FL1A but the last one I got did not seal well and my local parts guy mentioned that they had several complaints recently on them not sealing so I tried a Bosch filter. No leaks. It filters the oil I am assuming.

 
I agree with Jason. I find the Champion work well with Petronix that I had in my 1970 302 and with the Accell I have in my my 73 351C V2.

What that don't seem to be able to do is fix the bottom end engine knock...what's up with that!!!!????!!!

tim

+1 on the champion plugs. I run them as well. No issues what so ever running in an untouched 351c 2V with the exception of headers and Pertronix ignition. The intake manifold have never even been off the car. For the oil filter I ran the Motorcraft FL1A but the last one I got did not seal well and my local parts guy mentioned that they had several complaints recently on them not sealing so I tried a Bosch filter. No leaks. It filters the oil I am assuming.
 
Autolite 25s on mine

and

K&N gold HP3001 filter.

Ad01 verse ADo2 appears to be the heat range.

 
Personally I wouldn't run Champion plugs in a lawn mower let alone a 351C 4V. I had more failures with this brand than any other I've used over the years. I run Autolite 25 as a rule. Nothing wrong with a good old Fram PH8 oil filter either.

Just my vent on Champions, so don't get offended if you like crap plugs.

 
Autolites and Motorcraft FL1A.

The differences in the A.C. plugs is the heat range. There's no correlation between the numbers and the heat ranges on the rapidfire plugs, like there is on the standard plugs.

 
Last edited by a moderator:
Back
Top