Nope.

 

6AL is about a 30% jump in price. I chose to remove the factory fuel cutoff through programming and use the 6A. Definitely didnt want to hit the factory cutoff, but I'm not to comfortable hitting any rev limiter on juice.

 

So, do the msd 6al and digital 6 both offer the **** for setting the timing?

 

The 6A and 6AL does not have a timing retard function, although you can buy add on boxes to get the retard function. The Digital 6 has a dial to retard the timing.

All three boxes have a function that lets you retard timing 20 deg on startup, but I take it that's not what you were asking about.

 

On startup? You mean before you start the car up?

Dave has a crane digital system and **** inside his car that allows him to retard timing while the engine is running.

 

The 20 deg retard is only during startup, to help high compression motors turn over. I've never used that function on any of my msd boxes though.

The digital 6 has 2 dials on the box that can set retard from 0 to 9.9 deg - it's activated by applying power to one of the leads coming from the box.
http://www.msdignition.com/ignition_18_6520.htm

6AL does not have an adjustable timing retard:
http://www.msdignition.com/ignition_6_6420.htm

Here is MSD add-on box if you want an adjustable **** from MSD (I'd rather use the Digital 6 box to automatically pull timing when I spray, rather than have to manually dial it up or down though):
http://www.msdignition.com/tc_2.htm

And of course you'll get different features and setups with Crane or Mallory. I've always had good luck with MSD and prefer to stick with them...

 

Now, why is this guy at the local performance shop telling me that I should not get a digital 6 and that a digital 6 is not for everyday street use?

I understand that the digital 6 has its own system. Does this mean that it would tell me if I had a particular cylinder not firing?

I am still very confused on which system I should get. It seems that if my factory knock system controls the timing, that would mean that trying to adjust the timing with a different ignition system would be useless.

 

I think you need to consider why you want an ignition box. Unless your engine is Boosted, running nitrous, or operting at very high RPMs, it could be more trouble than what its worth.

I installed a Crane Hi-6 since I was also installing a blower. The first unit died after a few months. I figured it was due to the heat in the engine compartment so I installed a new box in the car on the passenger side kick panel. This box failed after a couple of years.

I've also heard that the Opti-spark doesn't hold up as well when using a spark amplifier, although mine did.

I never replaced the ignition box and since then my car has never failed to start. Without the box I dynoed over 440HP with a stock cam.

If you install a box I suggest you use the MSD harness. This will allow you to easily bypass the box should it fail.

 

I went with the Mallory 685, and I've never been happier. Fully digital, two rev limiters, built-in window switch, selectable retard for nitrous, and boost-referenced retard for forced induction. I think I paid ~$230 for mine from one of th sponsors on this site. It performs flawlessly and I'm extremely happy with it.

 

You don't have to actually know the parts, to sell them. Use the links I sent you, and call MSD and ask them directly, if you have doubts. Same with the other brands - look up the manufactures, and ask them your questions directly.

You do not want to rely on the knock sensor to pull timing, especially on boosted or nitrous applications. Regardless, the goal is to pull timing before knock, not have to compensate for knock by pulling timing after the fact.