Need Spark plug recommendation

[gomopar440]

Anybody know what kind/part number I should use?

I want to cut my MSD spark plug wires to legnth and I need to put some plugs in the heads get the distances and routing right. If I gotta buy plugs I'd like to just go ahead get the right ones I'll need to run this engine. I have the TTI 2&1/8" step headers mocked up so I can watch for any fitment/routing problems.

BTW: The compression is 10.5:1 and the 440-SR's have been through the ICH CNC porting. This is on a '75 440 based 511 stroker. I got the cam from Indy as well and I belive they said it was a SW509. I can check for the cam card later if needed. The engine is in my storage unit right now and not readily accesible.

[Chryco Psycho]

Champion has the RC12YC

[moparniac]

  I ran those as well.... but the accel 111's are a great choice also!

[Grancoupe]

Not endorsing NGK but they have agreat website. http://www.ngksparkplugs.com/tech_support/spark_plugs/index.asp?mode=nml this is worth reading to learn hoe the temperature of the plug can have agreat effect on your motor's performance. I personally found Autolite to have some of the best results from dyno results. They had the least amount of failures. I also use AC Delco's. I think the biggest issue is the temp of the plug not so much what brand you buy.

[moparniac]

I have used

NGK's cant remember#
Autolite 306's
Champions RC12YC
Accel 111's

and they are all good plugs but "tuning" YOUR MOTOR can only be done through trial and error! as all combos are a little different!
Most people today will say run the coldest plug as possible but they can foul easier than a hotter plug for "STREET DRIVING"...

I know a guy who runs edelbrock heads and a hot plug RC12YC and run's 10.12's and dont foul out on the street...
I also run the RC12YC  and havent had any problems yet...

But with a good ignition system like MSD can send a lot of spark and lessens the plugs chance of fouling!

I say run different plugs and see what your motor like best!

 

[gomopar440]

I say run different plugs and see what your motor like best!

It'll be a while before it runs. I'm still working on the wiring, the original 318, the exhaust, the chassis, the suspension, the fuel system, the body, the interior, the paint...

I'm hopping the 318 up a bit (4bbl, intake, cam, exhaust) after the wiring so I can at least enjoy the car a bit while I work on it. In the mean time, I want to get all the other stuff done before I tackle the 511. The 511 isn't on the calendar till next year at best.

I was digging through my parts for the stroker and found my plug wires. I didn't realise that these were the cut to fit kind when I got them. No biggie, I'd just want to assemble them so I don't loose any of the parts to them. I just wanted to know what plugs the stroker will need to get me in the ballpark when I'm ready to start it up. I didn't want to have to spend twice for plugs if I can get the best ones for it the first time.

[gomopar440]

Thanks to everyone for all the suggestions. I waited too long to go get the plugs and all the auto parts stores were already closed for the day. So, I went to go try to find them at Wally World. And I thought the parts counter guys at the auto chain stores were bad... I had to get their counter copy of the spark plug catalog and show them what a cross reference list was and where to find it. On top of that, they didn't even have the Champion RC12YC's I wanted. So, I had to find what they had available in the cross reference list. I ended up getting the Autolite Platinum AP3924's which didn't have the center ceramic part protrouding as far as the AP5224's. Given the compression ratio and the flat top pistons, I erred on the side of caution and stuck with the ones with the least amount of protrusion. If I have to change them later on so be it. For now, these plugs will at least allow me to get the plug wires routed and cut to size.

BTW: Anyone got the picture diagram that shows where the firing order falls on the distributor cap? I couldn't find my manual out in the garage.

[Chryco Psycho]

the firing order can be anywhere on the cap , you need to rotate the engine to TDC Firing on #1 cylinder & see where the rotor is pointed , it if it firing #6 the dist will have to be rotated 180* to line up correctly

[gomopar440]

Got a pic? 

I don't have the firing orders memorized. I also need to know which direction the dist shaft rotates when looking at it from the top.

[matt63]

...So, I went to go try to find them at Wally World. And I thought the parts counter guys at the auto chain stores were bad... I had to get their counter copy of the spark plug catalog and show them what a cross reference list was and where to find it. On top of that, they didn't even have the Champion RC12YC's I wanted. So, I had to find what they had available in the cross reference list. I ended up getting the Autolite Platinum AP3924's which didn't have the center ceramic part protrouding as far as the AP5224's. ..

It can be hard finding plugs at the local auto centers for older V8's nowadays.  I get my NGK's at a local engine builder's shop but have gone to the Mopar Performance dealer (I think they supplied Bosch??-they are in the catalog) and to a local auto wholesale store for even better selection.

[moper]

I have used NGK, NGK race, Champion race,and Autolites. The autolites are the cheapest, and work very well for me. I've found that aluminum heads like hotter heat range plugs. Especially with larger cams and pump fuel. It takes some effort to find the perfect plug for any engine. RC12 is a good place to start.

[Chryco Psycho]

firing order is 1-8-4-3-6-5-7-2
the rotation is Counterclockwise for big block , clockwise for small block

[gomopar440]

Ahh, thankee kindly 'O purveyor of Mopar knowledge.

Does this plug routing look ok to you? I have the front two plug wires on each side coming down under the headers and forward to the dist. The rears on both sides travel between the headers and the block around back and then over the top between the VC's and the intake to reach the dist. With the size of these headers I couldn't figure out any other way to get the back plug wires around them without getting way too close.

[Chryco Psycho]

you have to do what works to clear the headers , it looks OK from here

[kudakidd]

I have used NGK, NGK race, Champion race,and Autolites. The autolites are the cheapest, and work very well for me. I've found that aluminum heads like hotter heat range plugs. Especially with larger cams and pump fuel. It takes some effort to find the perfect plug for any engine. RC12 is a good place to start.

Autolite 75 (non resistor) here  OR Autolite 85 (resistor)