6AL box, where did you mount yours?

[BruceS]

Mine's under the front seat, drivers side. Had to splice wires, etc. but no issues in about 10 years.
I just didn't want to see it in the engine compartment.

Bruce

[fe66comet]

My theory on electronics is always a cool dry place, plus with heat comes resistance. Resistance reduces voltage output so I mount mine on the interior firewall somewhere it can get air flow or in the trunk works too if you size up the wires to 10 gauge. A little electrical grease helps on the connectors also to keep the nasty stuff out.

[amdscooter]

Allrighty, got under the hood yesterday and the box is up and running. Thanks again for the advise guys! Quick follow up question regarding spark plug gaps. The MSD guide recommends wider gaps starting with 10.5:1 compression motors .050~.060. Seeing as my 390 is a run of the mill 9.5:1 with a mild 268H cam, any need to increase the gap from the stock spec?

[plovett]

Quick follow up question regarding spark plug gaps. The MSD guide recommends wider gaps starting with 10.5:1 compression motors .050~.060. Seeing as my 390 is a run of the mill 9.5:1 with a mild 268H cam, any need to increase the gap from the stock spec?

I've experimented with wider plug gaps on my 10.5:1 428. Tried 0.040" - 0.50".   I've never found any gains.  I have an MSD 6AL and Blaster 2 coil.   No gains and sometimes it's more finicky with big gaps.  After experimenting, I always go back to somewhere around a 0.035" gap and it runs great again.  It's one of those "if it ain't broke" type scenarios.

I've also experimented with rounded off electrodes and always end up going back to the as delivered square cut deal.   What I'm saying is there is no need to reinvent the wheel here. 

JMO,

paulie

[cjshaker]

I agree with Paulie. Really nothing to gain by opening up the gap, especially on a mild or even an average performance engine. If it ignites the mixture, that's all it can do. With the MSD and Blaster coil you'd be fine going up to .040 if you wanted, but it won't change anything except for working your coil a bit harder.

[amdscooter]

^^^ Thanks for the confirmation guys! I'm going to toss a set of Autolite platinum's in (.035) and call the ignition system done. 

[ScotiaFE]

MSD ignitions do NOT like platinum plugs.

[fe66comet]

I could not find any suggestions for plugs from MSD except use the recommend plug for the application, I thought a resistor plug may be an issue but even those got a nod of approval when I called. The guy I talked to said use whatever plug you like basically, as long as the proper reach was used.

[ScotiaFE]

I have personal experience that the platinum will fail.
A copper core plug is what you need.
Last time I called MSD they said "use only copper core plug".
What happens is the high intensity of the multiple spark blows the platinum coating off
and then you get misfires.
Autolite 124's will work great.
 

[KMcCullah]

+1 on what Howie said. Autolite 124's work well with a 6AL and iron heads.

[MustangGT]

Been down there for 4 years since I bought the car and who knows how many years before that. I put it back there after restoring the engine bay since it has not given me any trouble.

[amdscooter]

Then 124's it is. Thanks all!