I am currently in the process of hooking up my 6A box in my car. It is a 350 with a carb and an in cap HEI distributor. I ahve the 4 pin module, attached is the wiring diagram they have for it. In the atttachement it says: NOTE: The GM Ignition Module is removed and replaced with the MSD PN 8861 Wire Harness Do i need to take out my ignition module in order to hook this up? I dont get it. Some one with experience please help. Also I dont have PN 8860 do I need to get it or can i splice wires together and hook it up?

i had to take it out and replace it im not sure if there's another way to do it

So is all of this worth it? do you feel a performance gain? do these boxes really work?

I really could'nt tell ya how much of a gain there is if any i still have to give it a good tune.

Just did this last weekend to a friend's truck, yes you need that part it should have come w/ your box, and yes it's worth it expecially on a carb it will start much faster and idle cleaner and smoother. By the way when I put mine on my camaro it cleanded up the idle so much the idle went from 800 to 1100!

Yea, I bought mine used so i wonder if i can even get that part, I got a good deal on mine, $20 at a swap meet. I just didnt get around to looking at it till now because I am working on my car running really good now, I put in an adjustable vacuum advance as well as new springs for the centrifugal advance. I gapped my plugs at .042 and have a Accell high spark coil.
I still need good wires, rotor, and cap and hook this up then and I should have optimum ignition... I think thanks for the advice

121-8861 is the part number in jegs i believe.

Thanks, for only $7 more i have to hook it up now... Are there any other parts I will need?

Whoa Whoa, I am pretty sure I can make that lol it is 2 wires and some retaining clips... I just really dont want to wait for shipping. Anyone think that it is a bad idea to make it?

If you use the right size wire, I don't see what it would hurt.