GM MSD boxes

[Andy4639]

I was given these this week and would like to know has anybody ever installed them on a truck before and noticed any thing better about how it runs. I don't think it's going to be worth it but figured I ask.

If you have a schematic of how it hooks up would be nice also.
It has a big weather plug on the GM igintion box.
Any and all info will be appreciated.

[Keith Seymore]

Does the "Heavy Duty Ignition" box have the rev limiter built in? Or is that what the other "red" box is?

I have an MSD 6AL box (and the installation instructions) but I don't think this is quite the same.

You might also try google and see if you can find the instructions for your set up on line.

K

[Andy4639]

Originally Posted by Keith Seymore

Does the "Heavy Duty Ignition" box have the rev limiter built in? Or is that what the other "red" box is?

I have an MSD 6AL box (and the installation instructions) but I don't think this is quite the same.

You might also try google and see if you can find the instructions for your set up on line.

K

The rev box is separate but has a direct connection to it. I don't know if either one will work. My buddy has been cleaning out his shop and just handing me stuff.
Yea a did some searching after posting it. I found one link that I think is correct.

GM MSD box #10037378---wiring code
-this information is for using the GM race box with a GM HEI distributor where the coil is inside the distributor cap.
-tested this box and wiring 6-2012 to verify it was compatible with the HEI.
---------------------------------------------------------------------------------------------------------------------------
-there is six wires that come out of the box and go to one 6 wire weatherpack plug.

#1 is red----gets 12vdc in from the key---turns on the MSD box.
-this red wire coming out of the 6 wire plug "T's"---one side going off to the key switch and the
other side going off to a 3 wire weather pack plug to provide power for a tachometer.

#2 is white--goes to the same 3 wire weather pack plug-----comes out the other side of the 3 wire
weather pack plug as a green wire that is the signal from the MSD box going to the tachometer.

(NOTE: this 3 wire weather pack plug is specifically to supply power/ground and pulse signals to the
tachometer.
-the other wire of the 3 wire plug is a black wire that comes thru both sides the 3 wire weatherpack
connector with a long black wire with a ¼“ ring end----coming out on the red/white wire side
and apparently to be connected to a ground somewhere.

-this black also comes out the other side along with the green and red.
-all three of these wires are about 5” long and are not terminated yet.

-This black wire is to be used as a ground specifically for the tachometer.
------------------------------------------------------------------
#3 is black---only wire that connects to the coil negative terminal.

#4 is orange--only wire that connect to the coil positive terminal.

(NOTE: in the HEI distributor cap there is a center terminal between the coil + and the coil - that is to be grounded---grounds the coil frame)
----------------------------------------------------------------------
#5 is green---connects to the HEI green (negative) magnetic trigger wire (you have to discard the HEI
module).

#6 is purple--connects to the HEI white (positive) magnetic trigger wire.
----------------------------------------------------------------------
-There is also a large red wire---goes directly to the battery positive.
-There is also a large black wire----goes directly to the battery negative.
------------------------------------------------------------------------
-there is also a 4 wire plug with yellow, white, brown and green, small short wires.
-this plug connects to a 10037379 rev limit control box which is included.
-This rev limit box needs two plug in chips---one is for the number of cylinders and the other is
for the rpm you want the limiter to work at.
-there is an 8 cylinder chip and a 7000rpm chip installed in the rev limiter.

Not sure I want to use it after reading all of this.

[The Rocknrod]

I think it's pretty cool with the GM labeling of an MSD box. And you can send it to MSD for updates to your situation.
https://forums.holley.com/showthread...301#post114301
An MSD Tech wrote:
On this particular MSD Ignition Box the wiring is as follows:

· Violet- (+) MAG pickup
· Green- (-) MAG pickup
· Orange- (+) Coil
· Black- (-) Coil
· White- Tach (this wire is white on box side and is brown on GM side of the plug)
· Red- (+) 12V switch/key on

On the opposite side of the box there are two more wires (Red & Black) which are hooked up as f0llows
· Red- (+) 12V battery
· Black (-) battery

If you are planning on using this box on a point’s style distributor you will have to send the box in for an update. If the box has already bin updated there will be a Gray, or White wire at the end of the box where the battery leads are. If it has no bin updated send the box to the address below and MSD will update your box for about $35.00 + shipping.

MSD Att: Repair
12120 Esther Lama Dock 5
El Paso, TX. 79936
Msdtech 13

[sweetk30]

my first truck had a whipped 350 in it that burnerd a lot of oil . i could get 5-6k miles more on a set of spark plugs . and before i swapped in a better engine and even after it always ran and started up a lot better i noticed over the old worn out hei dist .

if you have almost nothing in it then run it . but if you have to buy the whole setup its a toss up anymore unless you need it or want old school cool parts .

[68 P.O.S.]

I have both of those as well, but yet to hook them up. I've found the same info as listed above online. It's actually a MSD 6T (same as 6A, but with more vibration dampening), so you can go by the normal MSD schematic. The info online makes it sound more complicated than it is. Page 16: https://static.speedwaymotors.com/pdf/547-6400.pdf

[Andy4639]

Ok thank guy's. I will check out all these link's and see if I want to run it.

[mattfranklin]

That's pretty cool, even if only for the visual impact.

I don't remember the details, but there is a section describing the advantages in the mid-1980s (rev 6?) edition of "Chevy Power." I remember reading it and thinking, "Hey! Isn't that an MSD box?!"

Anyway, pretty cool find.

[biketopia]

If you have a spare HEI or 12v coil and plug wire you can test it before you go through the trouble of hooking it all up in the truck.

[Andy4639]

I got this from the same guy last week. He has been giving me all kinds of old school stuff since he is selling his shop. He is 76 years old and has retired. We have been good friends since 1982. He has all of his shop equipment for sell.
I'm very sad about him retiring but also understand why after his 4th heart attach. He is even selling his 65 Lemans also. He loves that car but his leg can't take the clutch anymore.
I'm very grateful to have him as a friend.

[68 P.O.S.]

Hey Andy, did you ever decide to hook this box up? I still haven't either lol