Cap, Rotor, and Plug Recommendation?

[Jackal]

I picked up a recurved Duraspark II from Scott at Reincarnation. I was stoked to see that it was a Motorcraft and not an import. I have an MSD 6AL and a Blaster II coil, but I need a cap and rotor. MSD tells me I need an 8450 cap & rotor kit, but this looks to me like a small cap for a Duraspark I. I called them back and was told that I also need an 8120 base, and that the rotor from the kit is of the appropriate height for this base, which means this is actually a large style cap. Black base with a red cap? Can anyone confirm? I'd just order a Motorcraft, but it too is a special order and cost more than the MSD parts.

I know that you can open the plug gap .01 or so from whatever stock is with the MSD, but I was wondering about temp range as well. I picked up a set of Motorcraft SP-420 / BSF42C copper plugs, but I wanted to make sure there wasn't a better starting place. This is a 390-4V with 406 small chamber heads getting shortys and eventually an intake.

[Nightmist66]

On my old dual point Motorcraft dist. I upgraded to Pertronix III and large cap. I went to Rockauto.com for the rotor and adapter, got both for just under $10.00. I searched under an '84 Mustang 5.0. Also I used the Crane dist. cap for the nice blue color and brass terminals.

[Drew Pojedinec]

Nothing wrong with a small cap if it is good quality.
I use the large cap too sometimes with the adapter.
Of note, they both take different plug wires, small cap is female and large cap is male connection.
Scotty is a good fella.

You say you have 406 heads?  what is the casting number on them?
I'd think you'd want a cool plug with such high compression heads, but I'm no expert there.
Plug gap, I always start around 35 and adjust as needed.

[Jackal]

Sh!t Drew you might have saved my ass again. I have newish Bosch Ultra Premium 7mm male wires w/ female cap. Not sure wth cap and rotor I want. If 7mm is sufficient, should I just consider a small cap? If so, whos? I prefer Motorcraft or MSD, but only because I'm a snob. If large cap, I may as well go with 8.5mm MSD wires I guess. If this is the route to go, can you confirm that I do in fact need the base and cap I posted above? I found that I need the MSD 84049 cable with the Blaster II coil, but that prob. isn't going to be long enough, even if I mount it on the driver's side. I plan to mount the MSD box on the pass. side.

From memory, they are C3AE 6090 C castings and the plugs I mentioned were for the 390-4v.

ETA: Side note, even with my relieved 7/8" drop base, my flex fuel line coming out of the Edy 600 cfm is pushed down at about a 45 deg. angle about 1.5-2" out from the fitting. Do you know if I can replace this fitting (looks like it unscrews) with something that will work better? Seems that my line is being pinched, not to mention any long-term effects from rubbing the base. I assume there is a a flexible stainless kit, but I have no idea how to spec it out to mate up to my hard line.

[Drew Pojedinec]

Obviously you can do whatever you want, but if it was me....

I'd use the plug wires I already have with a small cap.  I run a small cap on my car as I plan to go 2x4 carbs sometime in the near future and the large cap wouldn't fit.  Whenever you need to change plug wires, go with the MSD 8.5mm.  (I currently run the 8.5MSD wires and I like them a lot).  I tried out cheaper wires and the problem I ran into every time was that they'd break when I'd try to disconnect them from the plug.  I've got a new set of msd wires and one that I bought in 2005 and they still test perfectly.

If you wanted the large cap, you'd need new wires ($80) and the adapter (Cheapest at Rock auto for $3, put in a 1988 F150 with a 351 and go to the ignition section, they have cap adapters, and don't worry, you CAN paint the adapter and distributor cap).

On my truck I run the large cap:
http://www.summitracing.com/parts/msd-5504/overview/

On my car I run the small cap:
http://www.summitracing.com/parts/msd-5506

On paper at least, the large cap is probably better..... but better is relative.  This car never sees over 5,500 rpms and my truck never sees over 4,500 rpms.  At these levels I highly doubt it matters, and although I have no dyno to confirm or deny my feelings on this, I *suspect* it makes no difference as long as the parts are good quality.
It's kinda like asking yourself, "Do I want 150% overkill or 165% overkill?"

I don't really know anything about Edelbrock carburetors, but i suspect the issue is that the drop base was designed for a Holley 4150 style carb with it's fuel attachments.  I run a Holley 4010 on my truck and I had to be really picky with what filter base I used because of the same problem you are having.  Luckily in my truck, there is an absurd amount of clearance, even with a 2inch carb spacer   Not so lucky in the Galaxie. 

Running about the same compression you do, with roughly the same ignition (duraspark dizzt, msd box) I run these plugs: http://www.summitracing.com/parts/ngk-2227/overview/  Wes Adams suggested them to me, and they've worked out just fine.

[Drew Pojedinec]

Everyone loves pictures!

Small cap appearance (don't mind the crazy plug wires)



How the carb is attached to fuel lines:



I have a -6 to -8 adapter prior to the filter.  The fuel line on my car is -8 from inside the tank to this location.  Near driveside wheel well is a Carter HP electric pump and another looser screen filter.





1.5 inch drop base filter works fine with this setup:

[fekbmax]

Yey !!!!  Pictures. . LoL. 
Something even I can understand..   

[Nightmist66]

That's  a weird looking FE there, Drew.

Here's a pic of the setup in my old bucket of bolts. (Sorry, poor quality)

[Drew Pojedinec]

Jared,
If you look closely at the first picture, on the bottom, there is an FE part.
It is the alternator spacer made from an FE rocker shaft.

My Fe doesn't have a drop base filter, so it wouldn't have been as nice for a photo op.

[Nightmist66]

I can't  believe I missed that.

Btw, any FE is worthy of a photo op.

[Drew Pojedinec]

My FE is in my truck.
http://vid68.photobucket.com/albums/i6/DeepRootsNursery/MVI_0243_zps991ea3a7.mp4

It's got that wonky Holley 4010 which has a horizontal output for fuel lines.  weird carb, but I kinda like it.
No matter how hard I've tried it still keeps a mild stumble on REALLY hard acceleration, but otherwise is a pretty chill unit.

[Jackal]

Think I'll go ahead and order the MSD junk, though not sure why anyone would pay $57 for a housing adapter.

My concern is the 18" coil wire reaching the fender mounted Blaster SS coil. I was surprised to see a lack of FE Blaster SS mounting adapters in searching. Might have to rig something up.

Do you keep the FE under 4500 RPM intentionally?